Expert: Ramona Quilter - 5/15/2007

Question
Hello, I am trying to find out when I would have been most fertile. My period ended Dec. 22 2006. I had sex on new yrs eve/day. Had sex with some one else on Jan 6th. He did not ejaculate inside me. I found out I was pregnant later on in january. I am 18 weeks now. My dr. gave me a due date of oct 16, 2007. That date doesnt point to either person. It seems to point to a 3rd encounter. Is a woman more fertile before or after her period?  Thank you

Answer
Here is a website that calculates due dates:  
http://healthlink.mcw.edu/article/923526833.html

You begin with the first day of your last menstrual period which I estimate at Monday Dec. 18.  That being the case January 1st is the likely date of conception (and you had sex that day).  The 6th would be too late, too long after ovulation to result in pregnancy.  This calculator gives September 24th as a due date.  Sometimes doctors use other factors when figuring due dates but this is the most likely scenario.  I hope you like the guy you had sex with on New Years Eve.  He is the daddy of your child.  

This calculation is based on a normal period length of 28 days between cycles.  If your periods are farther apart than that, it is definitely possible that you might have gotten pregnant by the second fellow.  Without that additional information, I cannot be any more confident than the doctor.  You decide.  If your cycles average 35 or more days apart than the other guy is the father.