Kelvin, don't worry about it. If you're feeling comfortable and have no pain or discomfort, it may be that the sidearm delivery is your natural motion. Stay with it, and make the necessary adjustments to your mechanics. You'll be all right.
I remember that my pitching coach had this basic premise: that every pitcher has a natural motion, and the thing to do is to show that pitcher how to make the most of it. I was a natural sidearmer, having discovered this at the age of eleven, and I worked with it, and my coach helped me develop a number of things I could use with this delivery. You can do the same. :baseballpitcher: