Don't know what's going on...

Missed a pill (which rarely happens) about 2 weeks ago. I took it the next morning after I got home and haven't missed a pill since. I had sex with my boyfriend a couple times after that but he always pulls out and cums on my face or upper stomach. We had sex yesterday and all of a sudden I felt a huge pain in my stomach. It started in the uterus and felt like menstrual cramping but has since spread to my entire stomach. It hurts around my belly button when I move. Does anyone know what this could be? I also had a yeast infection last week, could it maybe of spread?