Rectal pain with period?

I'm experiencing some very strange symptoms and I'm really hoping it's just anxiety. My period started last Wednesday and, as usual, was super heavy Thursday and Friday with major cramping. Out of nowhere Friday night, I started experiencing some pretty strong rectal pain at the top of my anus. I couldn't sit down it hurt so badly. My sister said she sometimes experiences cramps in that area so I didn't think much of it. Saturday morning, my period abruptly stopped, making it much shorter than normal but the rectal pain continued all day. I'm feeling a bit constipated, too. I took a laxative Saturday evening and I'm still feeling kind of stopped up. Now it's Monday afternoon, my period is totally done but I'm still experiencing some rectal pain, and my lower back is also hurting at the moment. When I say rectal pain, it almost feels like pressure, but only when I move a certain way. Going to the bathroom doesn't hurt and walking around/exercising doesn't hurt. I have suffered from major health anxiety for YEARS now and this certainly isn't helping. Could this all be tied to my period? If so why is the rectal pain still there even since my period stopped early? Any chance there's an obstruction or impaction? Only place I feel pain is right st the top of my anus.