Hyperthyroidism in pregnancy ?

It happens: Get it definitively diagnosed and treated by an expert in the field (endocrinologist, experienced with treating endocrinopathies in pregnancy). Prior answers refer to this topic.

Yes: Not common, but certainly not rare. Most can be managed with certain types of anti-thyroid drugs (some are contraindicated in pregnancy - your OB and endocrinologist know this). Some require surgery, which is safest in the middle trimester, although surgery should be the exception, not the rule. If you need surgery find a surgeon who is expert in thyroidectomy for hyperthyroidism.