I am not the same anymore

After I found out on Sunday there was no heart beat I feel my life is crushing down. This is my 3rd miscarriage in a year. They tested my progesterone levels on Monday and it was 7 still wasn’t bleeding. On Tuesday I had my D & C. To make story short I went back to check my progesterone levels first time i miscarried and was 7 as well and doctors did not seen concern. I started doing my research and found out that’s very low. When I asked my doctor she said the levels go down during a miscarriage. I find it strange that since last year during my miscarriages they been 7. After my second miscarriage they checked me for blood clots and everything looked fine. I am starting to think the problem is with my progesterone. Can anybody explain if this is endeed correct???