Safety!

Okay so my boyfriend and I don't use condoms. We both lost it to each other so we don't bother with them, yes I know about the diseases that can be from birth but I feel better without. The point of the story is that I'm on the shot and my three months are going to be up on the 3rd. Should we use a condom to be on the safe side or no? 
We've gone without using condoms or birth control before on the pull out method but that was after my three months of depo ended. It had been six months since I had gotten my last shot. 
Anyways girls, opinions please!