It is likely the typical normal palpitations that we all get. If you want further medical investigation ask for a Holter or event monitor. They attach a small device to you and you wear it for a day or two. It records your palpitations for analysis. Then you will know absolutely for sure that what you have is no big deal and ease your worries. Also, being tired or sick will increase my palpitations significantly, I think that is typical. I am not a Dr, but my guess is when I am tired, my body makes more adrenalin (or equivalent) to compensate and that increases the palpitations. So, get some sleep!!
Hi Ash,
you should not be worried. My heart skips a beat on every down breath and they say that's natural for many people who grew up playing intense athletics. In extremely old people, the heart may just stop but if you are under 80 or so, the heart doesn't just stop beating. The deaths you hear about are from either a large heart that can't pump anymore or from a crazy electrical circuitry problem neither of which would be indicated by your symptoms.
One explaination is that you have a block of the electrical impulse which is quite common and benign. The more dangerous blocks would present differently than just a one-off skipped beat.