Is it normal to feel a pulse in your stomach by your belly button, does it mean your pregnant?

Not really, fetal pules are very week until way after the other obvious signs of pregnancy have kicked in. If you have any other signs, then go see a GYN/OB for a test to find out. If not, go see a G.P. and rule out any serious problems. It could also be something minor. For example, some people can feel their pulse in their fingers, earlobes, what-have-you. But I'd still see the G.P. just to be sure.
BTW, I am a Licensed CCT. (Certified Cardiographic Technician,) So I am familiar with blood flow and heart anatomy in both adult and fetal patients.

How are you feeling this? Is it possible the pulse you feel is actually coming from your fingertips as you press down?