HealthCareMagic is now Ask A Doctor - 24x7 | https://www.askadoctor24x7.com

Get your health question answered instantly from our pool of 18000+ doctors from over 80 specialties
159 Doctors Online

By proceeding, I accept the Terms and Conditions

Dr. Andrew Rynne
MD
Dr. Andrew Rynne

Family Physician

Exp 50 years

HCM Blog Instant Access to Doctors
HCM BlogQuestions Answered
HCM Blog Satisfaction

Will Plan B Work As Birth Control After Missing Several Doses Of Amethia Lo Birth Control Followed By Missed Periods?

Hi, I use Amethia Lo... the type of birth control where you only get periods a few times of year. Well I missed several doses and had unprotected sex, so I took Plan B, and now I am resuming my birth control as normal. My question is, will I have to wait till I get to the sugar pills to see if I had a period and to know it worked? Because I heard Plan B works by kind of flushing out your system, but if my BC is preventing periods, will it still work? Thank you! :(
Mon, 3 Feb 2014
Report Abuse
OBGYN,  's  Response
Hi,
Thanks for the query.

Since you have used Birth control pills irregularly and also used plan B, it is difficult to predict when you will have a period. Even with this, in most cases, for women using birth control pills, periods will come only after the active pills are over despite using plan B in the middle of the cycle.

Plan B works in more than 90% cases if taken properly. Concomitant use of both does not decrease the efficacy of plan B and it still works. It works by delaying ovulation and changing the lining of the uterus to prevent pregnancy from occurring. It does not work if pregnancy has already occurred.

The best way to know if you are pregnant in this case would be to take a pregnancy test at least 3-3 1/2 week after using plan B using a morning urine sample. If it is negative, chances of pregnancy resulting from the sexual act on that day [before you took plan B] are negligible.

Another way to know is wait for your period while taking the sugar pills, if it is delayed a pregnancy test 7 days after the missed period will help.

Hope you find this useful.
Thanks for using HCM, and have a good day.
Dr Madhuri Bagde
Consultant Obstetrician and Gynecologist
I find this answer helpful
Note: Revert back with your gynae reports to get a clear medical analysis by our expert Gynecologic Oncologist. Click here.
Disclaimer: These answers are for your information only and not intended to replace your relationship with your treating physician.
This is a short, free answer. For a more detailed, immediate answer, try our premium service [Sample answer]
Share on
 
Loading Online Doctors....
Will Plan B Work As Birth Control After Missing Several Doses Of Amethia Lo Birth Control Followed By Missed Periods?

Hi, Thanks for the query. Since you have used Birth control pills irregularly and also used plan B, it is difficult to predict when you will have a period. Even with this, in most cases, for women using birth control pills, periods will come only after the active pills are over despite using plan B in the middle of the cycle. Plan B works in more than 90% cases if taken properly. Concomitant use of both does not decrease the efficacy of plan B and it still works. It works by delaying ovulation and changing the lining of the uterus to prevent pregnancy from occurring. It does not work if pregnancy has already occurred. The best way to know if you are pregnant in this case would be to take a pregnancy test at least 3-3 1/2 week after using plan B using a morning urine sample. If it is negative, chances of pregnancy resulting from the sexual act on that day [before you took plan B] are negligible. Another way to know is wait for your period while taking the sugar pills, if it is delayed a pregnancy test 7 days after the missed period will help. Hope you find this useful. Thanks for using HCM, and have a good day. Dr Madhuri Bagde Consultant Obstetrician and Gynecologist