How effective is birth control if you have been on it for over three years and you had unprotected sex?

I had unprotected sex last month a few days before my period and again just the other day. I am a bit worried b/c with my last relationship I wasn't on the pill so I don't know how this whole concept works. I read that the pill prevents ovualtion from occurring, but does it really? I am supposed to get my period around the 13th of this month but now I am worried. Can anyone provide information for me?How effective is birth control if you have been on it for over three years and you had unprotected sex?
The pill (if taken correctly) is about 99.9% effective. It does prevent the release of an egg at the time of ovulation. Remember, while the pill prevents pregnancy it does not prevent STD's so safer sex still needs to be practiced.How effective is birth control if you have been on it for over three years and you had unprotected sex?
Are you currently on the pill? or did you quit at some point. If you quit, then you are at risk to get pregnant. By unprotected do you mean without a condom? I was on the pill for 10 years and had unprotected sex (w/o condom)for 10 years and never got pregnant.
how dumb are you to not wear a condom...birthcontrol isnt half as reliable as a condom...silly rabbit tricks are for kids..
The pill is 98% effective. There is always a chance of pregnancy but if you've been taking it regularly then your chances of getting pregnant will be slim.