Feeling sick... Why do I feel like this? What should I do?

Ok sooo..... I had sex 12+ hours ago and it's ovation time(highest peak). Husband ejaculated in me. About 2 hours ago I started feeling uncomfortable down there. Its almost the same feeling that I get when my period is trying to come on. Now I feel sick like I'm going to vomit and I still have that period feeling(doubt that it'll come this early though). Any advice would be helpful