What are the signs of a miscarriage?

Monday I found out I was pregnant. Still early on cause nothing was showing in sonogram on Wednesday, Thursday I started bleeding and was bleeding all day and night, Like a period not in much pain. And do see very tiny blood clots or peices of blood. Not filling up a pad every hour but bleeding like a period…Today still bleeding but not as much. Hospital couldnt tell me much but just to come back in a few days to check hcg level. Did I miscarry? Any of yall heard of this happen nd what was the out come ? Or been through this ? I’m beyond stressed out. Oh and I’ve taken 2 pregnancy test at home and they came out negative. The first one I took on Monday was positive. Then now after bleeding its negative…