Sorry if TMI

Im 25 weeks and I went to the toilet and had a wee jsut and when I wiped then was like a black mark on the tissue, it was only small and it wasn’t like mucus which is making me thinking maybe it was on the tissue already? (Gross I know) but I had opened a new tissue roll. I’m sure it was like a black and only small, nothing I’d seen before, around it was clear urine it was near when my finger was under the tissue.I don’t think it was blood as there was no red or brown tinge. I’ve been again and nothing and I’ve felt movement.

A car went into the back of my car this morning while stationary but I went up the hospital for them to check heart beat and heartbeat was fine and said that’s all they could do, it wasn’t a bad bump but because of this black mark I don’t know what it could be? Sorry if tmi