I Am A 42 Yr Old Female And Was Told

I am a 42 yr old female and was told as a teen I had a irregular heart beat caused likely from caffeine. I was told it wasn't life threatening. Over the years it has been very sporadic. When I have them they only last a few seconds and just feels like my breathe is taken away and a little pressure in my chest. In the last month I have had them a little more frequently but nothing alarming. The past week something new has started happening. When I am startled or excited I get chest pain, usually lasting about 20 seconds. It happened when watching a suspenseful movie (not really scary, just exciting), once when I was aggravated at someone, but not super mad, and once when I woke in the night because I thought I heard one of the kids vomiting. I have felt this pain a few times in my life when someone has jumped out and scared me (I'm assuming everyone has) but never this easily. Do you think this could be my heart and is it likely related to the irregular heartbeat?