Am I having a miscarriage?

I tested positive on a pregnancy test last week, I am 5w 1d today, I went to the bathroom tonight and passed these :( Does it seem like I’m having a miscarriage? I put a liner in, and I’m not bleeding red onto the liner just dark brown. This is the first time I’ve gotten pregnant and scheduled an OB next week, for the 2nd, but should I call them tomorrow about this? I have a really really really really bad feeling. My stomach was feeling full and like things were stretching like usual, but now I feel like pregnancy symptoms have stopped. Advice? :(

Update: I miscarried ☹️