please help me :(

I had sex 3 days ago and it feels like my body is trying to murder itself! Yesterday, I ran laps on a track and ended up dry heaving and almost fainting afterwards. I’m scared, but I know it’s too early to know if I’m pregnant or not. I need good advice since I’m cramping on constantly in my middle abdominal area. And no, we both do not have any STD’s or that sort of thing.

Thank you