Cramps after sex??

KeKe

I have been on the combination pill for 6 months. Sometimes I take it at different times of the day but I ALWAYS take it everyday, I've never missed one. I haven't gotten a period since I started taking the pill (my Dr. said this was fine). About 1.5 weeks ago I lost my virginity to my bf. We didn't use a condom but he pulled out (& I'm on the pill!). Now I'm having mild period like cramps! I just started my placebo pills today. What are the chances that I've gotten pregnant?? Why am I having cramps??