It's not really a skip, it's an extra beat. What is happening is that your heart is beating normally and then the left ventricle fires off a little early. There is then a brief pause that is perceived as a skip while the rest of the heart catches up. Because there is a little extra time, your heart fills a little more and the next beat feels harder.
As Ed said, it's most likely a common condition called a PVC, but get it checked. These are normal for about half of us in the world and are not dangerous unless there is underlying heart disease.
Hi, it means it would be wise if you have an ECG to check the sinus rhythm of your heart. It's very likely nothing to worry about, but always best to be safe.