Don't worry, I have read a lot of posts on here of others with similar symptoms.
I have a few friends who get palpitations and Dr always told them palpitations are harmless. I actually get palpitations if I eat anything with MSG in it. Some packets of crisps, especially bacon flavour have MSG in and give me palpitations.
Type in palpitations or missed heart beats in the search engine on here and it will bring up previous threads about it which may reassure you. Being anxious will also make you feel worse but hopefully when you read about others suffering same as you it should calm you.
If you are still worried, go to see your Dr for reassurance. Hope you feel better soon.