Plan B and regular birth control pills together?

I had unprotected sex with my fiance this morning and went to the pharmacist and got Plan B. I also filled my birth control pill prescription that I got from my doctor a few weeks ago. I've never been on birth control pills before but I've been meaning to go on it. Probably should have gone on them before this morning, but I'm on my period and so I didn't think it was terribly likely that I would get pregnant, but then I read all these stories of women getting pregnant while on their periods and decided not to chance it so I got the Plan B.

Anyway, so I just took the Plan B and then I was reading the directions for the birth control (it's Yasmine). It says that I can start it the Sunday after I get my period -- which would be today. But the pharmacist said that it would be a good idea to wait a few days after taking Plan B to start the Yasmine. Should I wait until my next period? Or should I just start the Yasmine in a couple days and figure it will only screw up my cycle a little?

One shouldn't really affect the other too much.

However, Plan B is likely to mess with your cycle a bit. If the pharmacist advised you to wait, then I would do that.

And yes, while it is unlikely that you will get pregnant if you have sex while on your period, it is not impossible.

Just as a heads up.. when I started birth control, I was told that the pills would not have full effect until the second month (second PACK) of pills, and that I should use a back up for the first month.

Hope this helps.