Can HIV Be Contracted Through Protected Sex?

Hi,

I've have got sex with an sexworker .. It was safety (with a condom) but I've realized that the condom was just halfrolled on my penis. So the opening and the top of my penis were protected but the other half was't protected (I didn't see any open wounds on this half part that wasn't protected with a condom) Is there any chance to get HIV on this way ? Please help me.