hi ,I am 28 weeks pregnant women and my thyroid has been detected as TSH = 8.0 when i was 5 months pregnant ,my gyn told me to contact PCP for medication ,she has given me synthroid 100mcg,after that my tsh was 0.56 and my t4 is 11.6 ,then again she increased my dose to 137 mcg and now my tsh is .159 ,what should i do is that is safe?