Miscarriage? (TMI)

I’m supposed to be 5 weeks and 3 days today. I had sex last night. When I went to go to the bathroom this morning, I saw a little piece of what looked like my uterus in the toilet bowl. I had light bleeding but most of it was darkish brown. It was really really light. Like one wipe was all. I’m scarred this could have to do with a miscarriage.. can someone help and tell me if this is normal?? I called my doctors office and my doctor is supposed to be calling me soon..