Hypothyroidism? Pituitary gland?

I've had hypothyroidism since I was about 4 years old. Never been to a endocrinologist. (I'm only turning 21) I lost my daughter back on May 29th due to premature labor (my ob only checked thyroid once in 19 weeks 3 days at beginning). I've been having pregnancy symptoms again but blood test showed up negative and I got my thyroid checked again and my doctor had to drop my medicine from 150mcg to 137 mcg to 100 mcg (starting 100 mcg tomorrow) in a month and 9 days time.. he says that's a big drop so he thinks something might be wrong with my pituitary gland so he referred me to a endocrinologist. My appointment isn't until October 18th though. I've been having all the normal symptoms of thyroid problems/pregnancy (even though i'm not pregnant) and i've been getting sharp pains randomly in the side of my head past few weeks. I'm stressing like crazy. Has anyone else went through this and everything turned out to be okay?