Nad are you 13 weeks now? Have you had your scan yet?
See gp and show nice guidelines key part here:
"*â—¦ Pregnant
â–ª Check TFTs immediately once pregnancy is confirmed.
▪ Discuss urgently with an endocrinologist regarding initiation of, or changes to, dosage of LT4 and TFT monitoring while waiting for review — trimester-specific TFT reference ranges may vary locally.*"
Some don't realise there's a different range to follow during pregnancy. Ask them to call hospital but really you should be seeing a consultant at your 12 week scan who would be managing you.
Ideally it should have been another raise at 3.5 (I was raised at that level by 50) but I do need to reassure you that you weren't hugely out of range. Also, if you have residual thyroid function your thyroid may be managing, however ideally you should be being monitored.
Unfortunately nice don't say anymore in the actual guidelines to keep below 2.5/3 tsh as they state to refer to an endo, who would do this. In practise this doesn't seem to happen much. I asked for the gp who didn't think I needed any extra this time (despite needing a lot more last time) to call an endocrinologist or the hospital, which she did and then fed back what they wanted. I was 3.5 and they did increase by 50 this time but it was a tad too much and I settled at an alternate day dose.
I must say that even if not pregnant, most people don't feel well till in the lower half of the reference range, and this is clearly stated even in the subclinical guidance in nice:
cks.nice.org.uk/hypothyroidism#!scenario:1
"Aim (in most people) to reach a stable TSH level in the lower half of the reference range (0.4–2.5 mU/L)."
Google local trust guidelines too and take them in. I've posted an example further up thread.