Is it natural to poo during masturbation?

When I was 17 I started jerking off frequently. Right before I would climax, I would let out a fart. Now that I am 20 I noticed about a week ago that I actually let out a turd. Should I consult a doctor about this? It's not like I have to poop while doing it, I don't feel a thing then all of the sudden I go. I'm not sure what to do! Any suggestions anyone?