
How To Determine The Date Of Conception?

Question: the first day of my last period was July 20. My due date is April 26. But doctors say I'm 17 weeks and 2 days pregnant. What day did I get pregnant?
Brief Answer:
Pregnancy age is calculated from your LMP
Detailed Answer:
Hi dear and thanks foe your query.
Don't worry because you are 17 weeks and 5 days calculated as per your last menstrual period on 20 July.
As per your menstrual periods ,ovulation have occurred around 3 August, and this may be date of conception of your baby, but we can't determine exactly conception date.
Hence as per your last menstrual periods doctor have calculate exactly that you are 17 weeks and 5 days pregnant.
All the best
Pregnancy age is calculated from your LMP
Detailed Answer:
Hi dear and thanks foe your query.
Don't worry because you are 17 weeks and 5 days calculated as per your last menstrual period on 20 July.
As per your menstrual periods ,ovulation have occurred around 3 August, and this may be date of conception of your baby, but we can't determine exactly conception date.
Hence as per your last menstrual periods doctor have calculate exactly that you are 17 weeks and 5 days pregnant.
All the best
Above answer was peer-reviewed by :
Dr. Arnab Banerjee


So I got pregnant arounfd August 3. Wouldn't that make me 15 weeks
Brief Answer:
No as per your last menstrual period
Detailed Answer:
Hi dear again.
We calculate pregnancy age from the last menstrual period, because exact date of conception is not known.
Hence as per your last menstrual periods you are 17 weeks and 2 days.
All the best
No as per your last menstrual period
Detailed Answer:
Hi dear again.
We calculate pregnancy age from the last menstrual period, because exact date of conception is not known.
Hence as per your last menstrual periods you are 17 weeks and 2 days.
All the best
Above answer was peer-reviewed by :
Dr. Vinay Bhardwaj


Well I just want to make sure that I wasn't pregnant before the 20th. Cause I had sex with another guy the 17 but then got my period and then I had sex with another guy and he came in me many times but te first guy pulle out but then we started having sex again. And I really hope it's not the first guy
Brief Answer:
You have conceived in the first week of August
Detailed Answer:
Hi dear again.
I understand your concern but don't worry because you have conceived on the first week of August.
Hence before 20 July, you haven't chances to get pregnant.
All the best
You have conceived in the first week of August
Detailed Answer:
Hi dear again.
I understand your concern but don't worry because you have conceived on the first week of August.
Hence before 20 July, you haven't chances to get pregnant.
All the best
Above answer was peer-reviewed by :
Dr. Vinay Bhardwaj


Say I had sex with both guys after the 20th. The first guy didn't cum inside me but he after he finished we had sex for a few more minutes. The other guy on the other hand.. Me and him had sex everyday since the first day of my period and he came in me every time. Who would be the father
Brief Answer:
Explanation is given below....
Detailed Answer:
Hi dear again.
I understand your concern but please be clear ,because you have mentioned that you have had intercourse with the first guy on 17 July (chances to conceive on this date are zero),than you have mentioned that you have had intercourse with both guys after 20 .
Did you remember exact date of the first guy?!
All the best
Explanation is given below....
Detailed Answer:
Hi dear again.
I understand your concern but please be clear ,because you have mentioned that you have had intercourse with the first guy on 17 July (chances to conceive on this date are zero),than you have mentioned that you have had intercourse with both guys after 20 .
Did you remember exact date of the first guy?!
All the best
Above answer was peer-reviewed by :
Dr. Prasad


It was either between July 13-17 or after August 3rd
Brief Answer:
After 3 rd August
Detailed Answer:
Hi dear again.
As I have mentioned above you have ovulated around the first week of August,hence during this time you have conceived.
The only test to determine the father of your baby with 100% accuracy is through DNA TEST alone.
ALL THE BEST
After 3 rd August
Detailed Answer:
Hi dear again.
As I have mentioned above you have ovulated around the first week of August,hence during this time you have conceived.
The only test to determine the father of your baby with 100% accuracy is through DNA TEST alone.
ALL THE BEST
Above answer was peer-reviewed by :
Dr. Prasad


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.do you think if I asked the doctor to do a dna test they would tell my boyfriend I wanted it done or would they ask him to just to make sure? if I asked them not to tell him I wanted it done
Brief Answer:
You should gain law acceptance
Detailed Answer:
Hi dear again .
As per your scenario with simple calculations we can't determine who the father is .
Hence the exact father can only determined by doing DNA test or prenatal paternity tests.
These tests can be done only after you will gain law acceptance .
These tests require only blood samples from the pregnant woman and the potential father,and are noninvasive tests
Hence the potential father should know for the procedure .
All he best
You should gain law acceptance
Detailed Answer:
Hi dear again .
As per your scenario with simple calculations we can't determine who the father is .
Hence the exact father can only determined by doing DNA test or prenatal paternity tests.
These tests can be done only after you will gain law acceptance .
These tests require only blood samples from the pregnant woman and the potential father,and are noninvasive tests
Hence the potential father should know for the procedure .
All he best
Note: Revert back with your gynae reports to get a clear medical analysis by our expert Gynecologic Oncologist. Click here.
Above answer was peer-reviewed by :
Dr. Sonia Raina

Answered by

Dr. Vjollce Mbiarra
OBGYN, Maternal and Fetal Medicine
Practicing since :2006
Answered : 1572 Questions
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