stomach pain

I'm 32 weeks and 3 days pregnant and for the last couple days I've been having pains go through my stomach mainly in the middle of my stomach. It's not constant it is off and on, no bleeding or discharge and the baby is moving around fine. Should I be worried? I'm a ftm and when I feel any kind of pain I don't know what it is. I don't know what a contraction is supposed to feel like so I just get a little worried. Anyone else going through this?