Emergency Contraception

I had sex on Tuesday (17 November) with this guy that I’ve been seeing for a little over a month now. We used protection and I am on birth control (pill). He was a little rough with the penetration when I was in a doggy style position and I believe the condom was slipping. Early Wednesday morning, I had a sharp stomach ache that last for about 20 minutes and the pain subsided. However, throughout the day, I had this weird feeling in my stomach. Early Thursday morning, the same stomach pain happened again around the same time early in the morning and the pain lasted for another 20-30 minutes. I went and took plan B. I have no idea what is going on. I have not been that consistent with my birth control. I started taking it again on Sunday (15 November) and before that I didn’t take it for 3 days. Was it too late to get the Plan B? Did I increase my risk for pregnancy? My last menstrual cycle was on October 25-29.