Worried....PLEASE HELP!

Tasiaaaa
So i am on BC (the pill) and I am 2 days late on my period, I have had a little bit of blood spotting.  y SO and I haven't had sex in the past 3 weeks! Also, I talked to my dr and she said that BC can lighten your period tramendously and only have spotting of blood, which I have, could I be pregnant?!?!?! Please help! I'm 16 and very nervous!!!!!!!