Hashi and ttc question

I have 3 beautiful girls right now. My husband and I never tried to get pregnant. We stopped using protection and within a month or 2 I was pregnant. I even had a miscarriage between my last 2 and the next month found out I was pregnant with by last. Anyways after baby number 3 when she was few months old i I was diagnosed with hashimoto. I have been taking my meds and have been regulated since 3 months after staying them. In March I went back to the Endo to have my blood drawn and get the all clear to get pregnant. My numbers were great and the Dr told me as soon as I find out I am pregnant to call right away and that I Erikr get regular blood drawn to monitor my levels. On April 23rd I found it I was pregnant and immediately called my endo who drew my blood about a week later. After getting the results she said my numbers were barely normal and upped my dose from 50 to 75. 2 weeks later I lost that pregnancy and I still haven't gotten pregnant. My Dr said she didn't want to draw blood until I have been on the new dose for 3 months. I honestly feel my levels are high. Could that have caused my miscarriage and could it be the reason why I haven't gotten pregnant yet? Even though she won't do a blood draw she claims my meds have nothing to do with the miscarriage and why I haven't gotten pregnant yet. What do you all think?