Hi. I'm A 39 Year Old Female And I've Been

Hi. I'm a 39 year old female and I've been having a strange heartbeat for the past few days. Everything will be fine and then it feels as if my heart beats one time extra hard or maybe skips a beat and then beats hard once to make up for it, and then I get a fluttery, nervous feeling. My arm tingles every so often, but I'm not sure if it's because of a tight muscle in my shoulder. I don't have any dizziness or nausea, but I'm getting a little concerned because it's happening so often.