Heart palpitations

I'm 19 weeks, 4 days. I've been having super bad heart palpitations for a while now. They'll show up for like a day straight, go away for like a week and then they will come back with a vengeance. My heart skips a beat like 3 times a minute. I get SLIGHTLY lightheaded but I almost think that's from the anxiety that they cause me.

I've had them on and off before pregnancy too, but I dont remember them ever being this bad.

Water helps sometimes, but not every time.

I have a cardiologist appointment on 1/28 to get them checked out.

My question: has anybody had this and it turned out to be something bad?? Every thing I've read seems like these are harmless, which is comforting, but I just need to see what else they could be... If that makes sense!

Thanks!!