Miscarriage.

Hello ladies, I wanted to know how would you know if you got a miscarriage. I woke up this morning and before I took a shower, I used the bathroom. After I was done using it, I saw a small piece of flesh inside the toilet bowel. I freaked out a little because me and my boyfriend just recently had sex. Like a 2-3 weeks ago. And I'm bleeding as well, but I don't really know if that means anything. I would like your opinions and experiences on how you dealt with the situation. I don't really know how to feel right now.