Just as a bit of background - I came off the pill a couple of years ago to start trying to conceive. After nothing happened for nearly two years other than inexplicable weight gain (I was exercising more than ever and watching what I ate, massively frustrating!), we started having fertility investigations.
It turned out that I had PCOS and 'borderline' hypothyroidism - I can't remember my exact levels, but my TSH was over 6. I was put on levothyroxine, and in two months I lost a stone and got pregnant. Yay!
I've had my dosage increased during pregnancy, and my levels are currently 3.8 TSH and 13 T4 (I'm 34 weeks gone).
Now, my endocrinologist is pretty adamant that I should stop levothyroxine as soon as the baby's born, because I was only borderline and was only prescribed it to increase my chance of conception. But I'm a bit concerned, mainly because I've read that having an underactive thyroid can damage the milk supply if you're planning to breastfeed - plus, the diagnosis explained a lot of symptoms (weight gain, tiredness, tendancy to feel the cold, thinning hair, etc), although some have crossover with PCOS.
I've also read (admittedly a lot of confusing) stuff about what sort of levels constitute 'normal' - mine have never been below 3.5, and were 5 - 6 until into the second trimester, which was when my dosage was increased.
There's part of me that just thinks I should trust the endocrinologist, as she's the expert and I'm just a numpty with Google, but I'm also a bit paranoid! Should I ask my GP for a second opinion?