Expert: Norman Solberg - 4/1/2009

Question
Hi, I have been on Yaz birth control for 2 months, 1 week, and 3 days. I take it everyday within a 1-15 min time period. I had my withdrawl bleeding on the 21st of this month and it lasted until about  the 27th or 28th. Usually when I have withdrawl bleeding, it is heavy in the middle like a period and then I notice lightness, or old (very very light brown) blood for about a couple days or so afterward. So 27th I pretty much ended the bleeding.
This past Saturday (the 28th) my boyfriend penetrated me for the first time without a condom. He has not previously ejaculated at all that day. (I have read that there is little to no sperm in precum as long as there has been no previous ejaculation) He did not ejaculate.
Then about a half an hour later, I had a flow of blood, almost like a period. It lasted a few minutes but was enough to soak my pants. It was a dark/ old blood looking.
My question is, did I do something wrong that would cause me to bleed like this? Did I ovulate? I don't want to become pregnant. Please, I would really appreciate your suggestions. What is the likelyhood that my birth control failed? Thank you so very much!!!

Answer
Dear Megan,
I don't think you did anything wrong.  You probably did not ovulate.  Bleeding that comes out after intercourse is usually blood that would have come out anyway, maybe a little later.  I don't think it means that your birth control failed, and I think your chance of being pregnant are very slight (less than 1%, which is true for anyone that takes her pills on time as you do).  Hopefully after you've been on the Yaz another month or two your periods will be lighter and you won't bleed afterwards.  Best wishes.