T.W.
My thyroid went crazy with my first pregnancy and I had to go to an endocrinologist every month and have bloodwork done. It didn't require meds, only monitoring until it went back to normal within a year of giving birth.
With my second preg. I could feel the changes happening again. I got monitored again, but it was less dramatic, so less monitoring.
Thyroid problems can cause you (and possibly the baby) serious long term effects, it is not something that you should ignore.
Meds or no meds, you still need to be monitored. And when your pregnant, they have to test your blood differently than if you are not. I would see a specialist until the problem corrects itself.