Anything bad going to happen? What is "anything bad" - getting pregnant? Well, you should've thought about that before you "inserted your d**k in her."
I am CERTAIN you must've heard SOMEWHERE in a sex ed class to use a condom unless you are okay with the possibility of having a baby! Seriously, you can get someone pregnant ANY time you have unprotected sex - it only takes ONE sperm cell and a single ejaculation has MILLIONS of them. So yes, the only advice I give to you know is to go with your girlfriend and get her a pregnancy test and MAKE SURE she's not pregnant and if she isn't, then thank your lucky stars and BE SAFE from then on.
I apologise for being mean to you in this comment, but if you and your girlfriend do not have enough sense to seek the proper education about having safe sex then you should not be having it. Yes, precautions can fail even if used correctly, but for the safety of you and your partner you may want to read up about them a bit more.