Did you self diagnose this?
An irregular heart rate
can be caused by a variety of things and there are a variety of different types of irregularity.
All of them need to be assessed medically however you will be pleased to know that some are quite harmless.
Is it reguarly irregular or just irregular every now and then. You can have some extra heart beats in amongst your normal ones called ectopics - these can be quite normal and happen to lots of people without any consequence.
It sounds like you need to go to a doctor ASAP just for your peace of mind so you are not so scared. Sometimes it is a case of medications, sometimes you need to have a minor procedure (under sedation) to send it back into rythym and sometimes you dont need to do anything at all.
Dont be scared - it depends on your age and your overall health too. If you are young and healthy then I would not worry but just get it checked to be safe.