Racing heart

Does anyone else have this thing where your heart will randomly race and you have to catch your breathe? I had it occasionally before pregnancy but it’s multiple times a day now. I’m 29 weeks. I called the doctor and they weren’t concerned 🤷🏼‍♀️ I also have a history of passing out for unknown reasons for the past like 10 years and they still said it’s fine. I am obviously not reassured 😆 I have a routine appointment scheduled for today so I’m going to bring it up again but just looking for others experiences.