[Harmony♥]

I agree with Brittany. Firstly, taking birth control that isn't yours could mess up your cycle, and could over-ride the birth control you normally take. Even if it is your mom's, you should refrain from doing this again. If you happen to forget your birth control next time you go home, don't take anyone else's.

Secondly, it's too early to tell if you're pregnant. It's only been a week, and usually, a pregnancy test won't be accurate until two weeks after unprotected sex. Give it some time, and then take a test to be sure. Since you DID take your mother's birth control, this may have affected you in a way where you could have gotten pregnant. From what I've heard (And correct me if I'm wrong anyone) birth control takes a month to become fully effective in our systems. Since you began taking a different brand, this may have happened to you.

Just wait it out. The bleeding could have been caused from taking your mom's birth control. Or, it could just be some spotting. In another week or so, take a pregnancy test and go from there.