Hypothyroidism

Anyone have Hypothyroidism and currently pregnant?? I'm starting to realize this may be the exact cause if my two miscarriages this year. Before I got pregnant the third time I started synthroid.. My only major symptom is hair loss! I used to have long hair and i thought being on birth control for a month caused issues all this time but it wasn't that. For 3 years  my hair especially in the back refuses to grow now, out of no where I have a small patch of hair in the back around the lower middle (the bottom sides are long). Has anyone had hair loss/ thinning issues??? This is really been depressing for me for the last three years.. Any suggestions on how to get my hair to grow back while having this???