urinating blood clots

Emily
Hello everyone🙂
I'm trying to keep my chin up and not overreact but I'm going through something rough. A week ago I had sex with my boyfriend after not having sex for a month and it was really rough. Fantastic, but the next day I started my period and felt pressure like I had to pee when I didn't. I had MASSIVE cramps. Absolute hell. Didn't leave the bed and couch all day. Pressure pee feeling lasted for a couple days, then went away. 4 days ago I got the urge to pee every 2 minutes and would only pee a little for about 4 hours one morning. That morning I also peed blood. A lot of it. Then I peed some mucous-y blood clots. 
Weird.
Ok.
It went away after I did yoga. Even the urge to pee. Now I'm suddenly peeing smaller blood clots again. I'm going to a doctor tomorrow. I have no other symptoms. 
So, blood pee, blood clot pee, discomfort while peeing, initially bad cramps, yeah. 
Do you guys think I have bladder cancer, a UTI (specifically bladder infection), or something else?
Any response would help. I'd rather know what's going on then wonder and just be hopeful 😊