HELP...

I made a big mistake, I'm 16...I'm a straight A student, I always told myself I wouldn't end up like my mother . ( pregnant at a young age) but I did loose my virginity to my best guy friend.....we used a condom, it was use correctly but I'm still freaked out, cause I have goals in life , I'm not ready for a baby...I don't think I am pregnant I'm just worried. I was bleeding today ( might be period) but it stopped-ish. Is it my period??