My girlfriend and I of a year and a half have been fooling around lately. We've gotten to the point where we've taken off clothes all the way down to our underwear. One time she was wearing a g-string and was wet and I was going inside of her but I still had my boxers on. I may have pre-cummed but I know that I didn't ejaculate in her. My question is what are the chances of her being pregnant from our encounter that afternoon? Is this something that needs to be checked or should I just wait and see? This has gotten me fairly shaken up and I know that we shouldn't have gotten into this situation in the first place but I would just like some input.