Having Spotting Two Weeks After Period?!?

Marie
I had my period two weeks and the week before that my boyfriend and I had unprotected sex. I'm on birth control but around that time we had sex I slept over my alarm to take my pill a few times and I would take it a hour late. 
Now I'm having light brown spotting/discharge. I'm starting to freak out cause online it's saying pregnant and implantation bleeding and I really hope I'm not pregnant. Am I overreacting?