Solid stuff

I'm adding this is anon because it's kinda gross. I'm pretty sure other women get it but I feel uncomfortable. 
Ok on topic, I just got my period on Sunday this month, it has been really weird. It started really bright, almost a neon color. But now, it is almost black. It's really dark, I'm using a pad to kinda look at what is goin on. When I change it, I have this solid stuff, I realize it could be the lining but I poked it and it wasn't like normal, it was rock solid with mucus around it. 
I've been having unprotected sex so maybe I've been pregnant and not know of it. I've been feeling nauseous and tender breasts and my period was late. I didn't take a test so I don't know if I was or wasn't. But if I was, I'm scared this could've been a miscarriage. I don't have insurance, so I can't go to a doctor. But any insight from here would help me take the next step. Thank you.