I agree with Big Cat. Chances of you being pregnant are less than if you were not taking birth control. However, no form of birth control is 100% effective. Give it a little more time, if your period does not come, take a pregnancy test to be sure.
I had unprotected sex on Sat. I'm on birth control, so my expected period date was Sun. But, I haven't started yet; however, I usually don't start until Tues. or Wed. Is it possible for me to be pregnant?
It depends if your period's late, you had unprotected sex Saturday this is Monday going on Tuesday in some places. You need to maybe wait to Wednesday. You know birth control medication can mess female's periods up too? It's way to early to know if your pregnant. If you're using birth control that should protect you but not all birth control is 100 percent safe to protect a female from getting pregnant. Also, birth control medication is not enough to protect a female from diseases either, you got tell the guy to use a condom.