My doctors appointment

Went to my doctor for a check up, after my MC. I asked him if he would check for low progesterone and he didn’t want to. He said that progesterone and estrogen, have to do more with mensuration, rather then pregnancy... He said if I MC more then once they would usually do tests for like thyroid and everything, which we tested last year, because of something unrelated, but he said was it normal, as well as my ultrasounds... he just told me that more then likely this was due to cell division, and that it just wasn’t growing properly.... I want to trust my doctor, because he sound like he knows what he’s talking about, and he’s never lead me wrong before....

Is low progesterone and thyroid connected?