Could this be a miscarriage or something else?

I had unprotected when I ovulated. About 4 days after I had mild cramps and odd feelings in my lower abdomen. This lasted up until the day my period was due. I also had nausea, headaches, sensitive to smells and back aches from the week before my period was due until a week after if was due. On the date I expected my period I took a dollar tree test (which I used with my first pregnancy and was correct) it was negative. 2 days later all my symptoms started to fade until they disappeared Exactly 1 week late abd I got my period. It seemed to be normal not too heavy but not light which is normal for me. Then I stopped bleeding abd used a panty liner for 4 hours felt a gush and went to the bathroom abd saw a large piece of tissue about the size of my pink finger. It looked like it was rolled up or something but I could see ridges in it like a prune or something tmi I know so sorry. But it didn't have much blood on it. Then for the next 6 hours I used 4 different super plus tampons then it just stopped and I haven't bled since (2 days) was that just uterine lining or something else. I called my gyno and she informed me that if it was a mc then it was complete and no further action is required unless I continue to bleed, spot or have cramps or fever. I have none of those symptoms and feel absolutely normal. Any suggestions. It's really puzzling me. Thanks