hyerthyriodism creates brittle bones and can really hurt over time. during pregnancy the extra weight thas on your pelvic bones will prolly make it hurt more tha someone who doesnt have it. but to be on the safe side talk to your doctor im sure they have something out there that can help with the pain so you can still enjoy being pregnant.
Usually if you have a thyroid problem you may not be able to conceive, depending on how low or high your levels are. In my circumstance I was told my thyroid was a little high while I was pregnant, but I was not given any medication. Doctor said pregnancy would throw off the levels anyway. I lost that baby by the way, and I think it had to do with my hormone levels. If you are concerned talk to your doctor.