⚠ Help, is it normal?? ⚠ 36w5d

Okay so I've had this a couple times the past couple weeks and have shaken it off mainly because I don't want to make the trip to the hospital to be told it's nothing and because I thought it was connected to maybe pre-eclampsia but I have no protein in my urine... So when I'm just sitting down or laying down even I'll get this lightheaded feeling along with what feels like what I can only discribe as heart palpations or an irregular heart beat and it'll be hard to breath.. I was only experiencing it once or twice a day but today it's happened quite a lot and I'm considering going in when my husband gets home because it isn't going away... but before I do I just want to make sure it's not some weird normal pregnancy related thing.