Anyone have an abnormal heart rate while pregnant?

Yourself, not the baby. I’m 18 weeks. This is day two of it for me. It feels like after you hold your breath for a while and then your heart beats really hard and heavy to catch up. I saw my doctor and did an EKG yesterday and she said it’s abnormal but not so bad that she couldn’t send me home. I have a referral to go to cardiology but it’ll be awhile before I can get an appointment to see them and my heartbeat feels so fast and hard today. I know it’s supposed to pickup some because of the extra blood flow but it seems like a lot.