Pretty sure I had a miscarriage yesterday...

I am very upset we found out last week I was pregnant. I am 6 weeks and Monday I woke up with blood. The Tuesday I started clotting. I went to doctors got my Rogain shot because I am o-. Blood has slowed down but yesterday the clots where so big I had to have had one. I have never miscarried so don't know what to do. This would have been baby number 4. Advise would be great right now. I go back thursday morning to see if my levels get higher for blood work. But I don't think they will be...help...anyone been in this situation...