It can be. Many times we worry about simple things in life. Sometimes you have to change habits and it clears up. My dad had a very difficult breathing problem and we found out that it was from the laptop being on his chest when he was on his bed. Visit a doctor to get a checkup, but most likely you are probably fine. A warning to you from my past experience, don't try to do a self diagnosis. You are not a doctor and the computer can't be a doctor for you so it's best to visit a doctor and keep your self free of worry.