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How To Determine The Date Of Conception?

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Posted on Thu, 10 Dec 2015
Question: The first day of my last period was july 20. My due date is april 26. Doc says im 17 wks and 3 days. What day did i get pregnant?
doctor
Answered by Dr. Jacqueline Brown (24 minutes later)
Brief Answer:
I can give you a window of possible conception dates

Detailed Answer:
Hello, and I hope I can help you today.

Estimating the date of conception always has a margin of error because it takes time
for the egg and sperm to find each other so you don't conceive until even up to 3 days later than when you may have had sex. Also sperm can live inside you for even up to 5 days. So I can only give you a window of time that you could have conceived, which in your case was from between 7/24 and 8/4.

It is not possible to determine dating more accurately than that, especially with a second trimester ultrasound. In the second trimester, the margin of error can even be off by up to 2 weeks! So the first day of your last period is usually the most reliable way to date a pregnancy.

I hope I was able to answer your question today and that my advice was helpful. Of you need anything further, please do not hesitate to contact me.

Best wishes for the rest of the pregnancy,

Dr. Brown
Above answer was peer-reviewed by : Dr. Vinay Bhardwaj
doctor
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Follow up: Dr. Jacqueline Brown (1 hour later)
I just want to make aure that there was noway i could have gotten pregnant before the 20th co sidering the fact that i had sex with a guy on the 17. But he didnt cum in me, he pulled out but then we contuied to have sex. Everyday after that until like now me and this other guy have had sex (even during my period) and he has cum in me many times. And i really want him to be the dad. So i just want to make sure that i got pregnant after i had my period
doctor
Answered by Dr. Jacqueline Brown (11 minutes later)
Brief Answer:
It is not possible to get pregnant and then have a normal menstrual period

Detailed Answer:
Hello again, and I am happy to answer your follow-up question. The menstrual cycle that preceded your pregnancy which started on July 20 was the beginning of the cycle you conceived. There is no way you could have conceived or have had semen present from your previous cycle at the time of your fertile window.

So I think that you can be confident that your current partner is the father of your unborn child.

I hope that this information is reassuring, and good luck with the rest of the pregnancy,

Dr. Brown
Above answer was peer-reviewed by : Dr. Arnab Banerjee
doctor
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Follow up: Dr. Jacqueline Brown (23 minutes later)
Say I had sex with both guys after the 20th. The first guy didn't cum inside me but after he finished we had sex for a few more minutes. The other guy and I had sex everyday since I started my period till I find out I was pregnant, and he came in me every time. Who do you think the father would be.
doctor
Answered by Dr. Jacqueline Brown (1 hour later)
Brief Answer:
It makes sense that the partner you were with more often is the father

Detailed Answer:
Hello again,

There is no way to say by absolute certainly, but if you only had sex once with the other partner and he did not ejaculate inside you, it is unlikely you conceived from that encounter. Therefore the person you were with more frequently most likely is the father.

No one can say 100 percent that it is impossible, but I really think you can rest assured.

I hope this information is reassuring.

Dr. Brown
Above answer was peer-reviewed by : Dr. Arnab Banerjee
doctor
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Follow up: Dr. Jacqueline Brown (11 minutes later)
What's the possibility of getting pregnant when a guy pulls out to finish but wait a couple of minutes and then start having sex again
doctor
Answered by Dr. Jacqueline Brown (10 minutes later)
Brief Answer:
It is extremely low

Detailed Answer:
The only issue would be if he still had semen on the tip of his penis when he inserted it again. However, sperm dies when exposed to air so in that scenario it is unlikely any would have survived anyway.

Couples who use withdrawal as a form of contraception only have a 15 percent chance of conceiving per year.

So again, from a single encounter in your scenario, and especially if your partner cleaned himself before reinserting, i really do not think you need to worry about this partner being the father of your child.

Let me know if you need anything further,

Dr. Brown
Above answer was peer-reviewed by : Dr. Arnab Banerjee
doctor
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Follow up: Dr. Jacqueline Brown (26 minutes later)
But what if he didnt clean himself off. And then what. Especially if it was close to when i was conceiving and ovulating
doctor
Answered by Dr. Jacqueline Brown (1 hour later)
Brief Answer:
Given the information I have so far that is not really possible

Detailed Answer:
Hello again,

When I answered your previous question, I was replying assuming the information you gave me was correct; that your last period started on the 17th and that you only had sex once with this other partner- and that he did not ejaculate inside you, and hypothetically the sex occurred on the 20th. This is actually not during the most likely fertile time of your cycle- if you have a 28 day cycle your ovulation likely occurred around 7/31.

So again, if you were with this other man at the third day of your cycle even if some sperm got in you, you likely weren't ovulating and do not have to worry about pregnancy.

But no one will ever be able to give you a quantitative answer about how much live sperm could have remained on his penis and/or if you were ovulating around that time. Any woman who has genital contact with semen in or very close to the vagina is at risk for pregnancy.

But again, given the dates you have given me, it is most likely that your current partner is the father. Beyond that, there is no way to know for sure other than by taking a paternity test. No one will ever be able to tell you that pregnancy is impossible from your situation, but we need to try to use logic to try to make an educated guess that multiple episodes of unprotected intercourse are more likely to achieve pregnancy than a single encounter with someone who did not ejaculate inside you.

So I hope you can relax a little bit about this issue and remember just because something is possible, does not mean that it's likely to occur.

Take care,

Dr. Brown
Above answer was peer-reviewed by : Dr. Prasad
doctor
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Follow up: Dr. Jacqueline Brown (15 minutes later)
He said we had sex the 17 and my period was the 20. But idk if he is just saying that because he doesnt want to be blamed for being the dad. So saying we did have sex after my period then who would most likely being the dad if we only had sex once and he didnt cum inside me but he didnt wipe it off when he put it back in me compared to my boyfriend who me and him had sex since the first day of my period and he came im me every time
doctor
Answered by Dr. Jacqueline Brown (10 minutes later)
Brief Answer:
I answered that in the last question...

Detailed Answer:
Maybe it might be easier to think of it this way... were you with him around July 31st?

Because that is the most likely time of ovulation for you and most likely conception occurred then.

So if you can remember when you had sex with him, all you need to figure out if it was around that time.

If you can't remember, even if you were at your fertile time, it is only theoretical that you can get pregnant from sperm outside of penetration. I certainly never had a patient get pregnant without ejaculation inside, ever.

So the answer is still the same- Common sense- the guy you were with the most (your current partner) is the father.

I am sorry it is impossible to completely say any more accurately than that, but I really don't think you have to worry.
Above answer was peer-reviewed by : Dr. Prasad
doctor
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Follow up: Dr. Jacqueline Brown (9 minutes later)
It was either july 13-17 or after august 3
doctor
Answered by Dr. Jacqueline Brown (25 minutes later)
Brief Answer:
So there is a chance that you were with him where you were fertile....

Detailed Answer:
But again, as I said before, it doesn't change the situation.

Your chance of pregnancy no matter what time in your cycle with one encounter where the man did not ejaculate inside you is very, very low. But not impossible, because nothing except abstinence gives you a guarantee.

I know it is hard, but the best I can ever say is that it is next to impossible..., and then you can decide later if you want to do a paternity test. There is a lot of uncertainty in pregnancy; even with proper medical care no one is guaranteed a perfect baby. But, the greatest chance is that everything will be fine. And the same thing goes with your situation.

Good luck going forward, and I hope you have a healthy rest of the pregnancy,

Dr. Brown
Above answer was peer-reviewed by : Dr. Prasad
doctor
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Follow up: Dr. Jacqueline Brown (12 minutes later)
Thank you
doctor
Answered by Dr. Jacqueline Brown (10 hours later)
Brief Answer:
You are welcome

Detailed Answer:
You are welcome, and thank you for using healthcaremagic.com
Above answer was peer-reviewed by : Dr. Vaishalee Punj
doctor
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Follow up: Dr. Jacqueline Brown (30 minutes later)
Ok we what if the night before my boyfriend came. In me and then the next day the other guy maybe got a little bit in me. I had sex with the other guy either April 13-17 or After August 3rd
doctor
Answered by Dr. Jacqueline Brown (1 hour later)
Brief Answer:
I cannot give you any more information than in the previous answers

Detailed Answer:
As I said previously, you most likely ovulated on the 31st of July. So there is a chance that you could have conceived if someone ejaculated inside you or near your vagina around that time.

There is nothing further or more specific I can add no matter what you tell me about the timing of your encounter with this other man.

You have an extremely low chance of having gotten pregnant from this other individual. However, it is not impossible. Unfortunately, it is not possible for anyone who has sexual activity with two different partners around their fertile time to know for sure who the father is.

You may want to seek a second opinion from another physician if the information I've given to you is not satisfactory. However, it is doubtful that any other gynecologist would be able to tell you anymore specifically about your risk of having been pregnant by the second partner in your situation.

The only way you will ever be able to know for sure about the paternity of your child is by doing a paternity test after it is born. You also may want to discuss this whole issue with your prenatal care provider.

I'm sorry about how anxiety provoking the situation must be for you. But asking the same question again and again in different terms is not going get you closer to an answer that you want to hear.

If you do not have any other different questions, please close our encounter and if you would like to seek an opinion from second physician you are welcome to do so at healthcaremagic.com

Sincerely, Dr. Brown


Above answer was peer-reviewed by : Dr. Vaishalee Punj
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Answered by
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Dr. Jacqueline Brown

OBGYN

Practicing since :1996

Answered : 1425 Questions

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How To Determine The Date Of Conception?

Brief Answer: I can give you a window of possible conception dates Detailed Answer: Hello, and I hope I can help you today. Estimating the date of conception always has a margin of error because it takes time for the egg and sperm to find each other so you don't conceive until even up to 3 days later than when you may have had sex. Also sperm can live inside you for even up to 5 days. So I can only give you a window of time that you could have conceived, which in your case was from between 7/24 and 8/4. It is not possible to determine dating more accurately than that, especially with a second trimester ultrasound. In the second trimester, the margin of error can even be off by up to 2 weeks! So the first day of your last period is usually the most reliable way to date a pregnancy. I hope I was able to answer your question today and that my advice was helpful. Of you need anything further, please do not hesitate to contact me. Best wishes for the rest of the pregnancy, Dr. Brown