period? or miscarriage? I need help

Okay so last night I hanged out with my bf, we had sex but then after a while he hit something and i felt a sharp pain but I continued doing whatever until he finished. Then all of a sudden I felt a really bad sharp pain just where my cervix is....I got home that night and my lower abdominal right where my cervix is was swollen. Now rn I got a painful pain there again and I went to the bathroom...I peed and then I wiped myself. When I looked at the toiletpaper it had blood...a light red. Then I looked in the toilet and there was a little blood and a small piece of blood clot.

What could it be?!? I was feeling nauseous and I had headaches like 2 weeks ago for a week straight.  What could I have wrong?