So we had sex tonight and he put the condom on backwards, but realized what happened and proceeded to put it on the right way. This all happened rather quickly. 

Should I be concerned of pregnancy? 

UPDATE: a condom rolls on one way, but as he put the condom on, he saw he was rolling it onto his penis the incorrect way, flipped the condom correctly (meaning he was putting it on inside out) then we had sex. i'm concerned if possible precum on the condom.