someone help me.

So last week I missed my period so I took a pregnancy test. It was positive and we were so excited because we have been trying to have another baby for awhile. Well I started to spot and I didn't think nothing of it because I had a period with my daughter for three days at the beginning of that pregnancy. But then I started bleeding heavily but I tried to wait till my doctors appointment because I wasn't in any pain. Well today I had some really bad cramping then I passed this blood clot looking thing and it scared me because I looked up some pictures of miscarriages and it looked like that but I still don't know for sure and I called my doctor and I have an appointment on Thursday but I just wanted to know if this sounded and looked like I have had a miscarriage.