Thyroid issues early pregnancy?

Anybody have thyroid issues and pregnancy? I just had my yearly physical on November before I was pregnant and my thyroid was fine. I started noticing heart palpitations though a few weeks ago and my cardiologist tested a bunch of blood and my thyroid levels were very very low which actually she said means hyper thyroid. didn’t say to do much right now I’m going to an endocrinologist in two weeks but of course in my mind I’m very nervous about why the levels are so low. Just wanted to know if anyone else has experienced this in pregnancy? I did read somewhere where It can go back to normal in trimester 2 when the hCG levels drop.