I have also got problems with underactive thyroid, but have also been told that the baby starts making its own thyroid after the first trimester so after this the mothers level is less critical. This is why as we haven't got my thyroid replacement levels quite right yet I have a blood test every three weeks but she indicated that once out of first trimester can have BT's 6-8 weeks apart.

The range for TSH I get from my doctor is 0.3 to 5.00 so you would actually be within the normal range according to that.

Is also can get a bit confusing because I thought low TSH means overactive thyroid, as Thyroid Stimulating Hormone gets higher when you have low thyroid e.g. at one point mine was 90 because my T4 was only 5 (should be 9-19), whereas now it is 1.53 and T4 is now right at 14.5. (Often they only check T4 if your TSH is out of range).

I found researching on internet totally confused me and there seems to be so much conflicting info, so like previous poster just trust the endocrinoligist now and fingers crossed scans etc show all ok so far.