Miscarriage

Ok so I took a test last Wednesday and it was positive. Same day I took the test started spotting brown that has now turned to red clots. According to my last cycle I should be 7wks2days. Well I went to the dr today and the preg test there was positive too and I was told that they could not confirm or deny a miscarriage right now because my cervix is closed and my lining is really thick. She said I am either really early in my pregancy because they did not see a sac or anything just debri/blood in my uterus or I am having a m/c but they dont know for sure. So I have to go back next week for another ultrasound plus they did an hcg draw. I am pretty much convinced that is a m/c because this will be my 3rd one in a row. What do you guys think? Has anyone ever had this to happen?