PLEASE HELP! Can't Stop Worrying, But It Could Be Nothing....

[anonymousworryworm]

Please read all the details here before replying.
I am a man who has been dating my girlfriend for a few months. We only recently started doing more than getting to third base.
I'll try to keep this as brief as possible : here is my issue.
She recently told me that she is going to be having her third cycle in one month, and that it doesn't make sense as to why. She did start taking birth control about a month ago (I'm not sure which kind), so I don't know if that could have anything to do with it. Naturally, I'm starting to freak out worrying about pregnancy.
Here's the thing though: I've never "finished" inside her. We had sex for the first time a few days ago and I pulled out WELL before ejaculation. I've heard scary stories of pre-ejaculate (pre-***) being able to, in rare cases, impregnate a woman.
There have been a few other times where I've put it in her, if only momentarily, just as a tease, but there was definitely some leakage on my end (again, never cumming inside her).
I've been scouring the web trying to achieve some peace of mind. I'm really worried. Definitely am in no way ready to become a father.
I know that given what I've said, it's very unlikely, but I would really like to hear it from people that know more about it than myself.
She seems to be a little worried as well, but (annoyingly) not worried enough to take a pregnancy test or ask her doctor about it.
Please please please tell me that I'm just being paranoid and have nothing to worry abut.
Thank you so much!!