So how does not taking a test change anything?

Protected sex when her period was due doesn't usually turn into a pregnancy.

Wait until 14 days AFTER the sexual incident and take a pregnancy test.

If you are old enough to have sex, you two are old enough to do a 'creepy' pregnancy test.

how is it going to be "creepy" if you think that you shouldnt even be having sex because you are putting yourself at risk for this "creepiness" and you should be old enough to know that.. so have her take a test and wait for that "creepy" result.

"creepy as hell?" okay please stop having sex now.

If your girlfriend is late on her period, it could be for multiple reasons, however one of the main reasons is that in fact she could be pregnant.

The only way to verify this pregnancy aside from waiting a few months to see if she continueally does not have periods and her stomach enlarges, is to infact take a test. Its not something that you can avoid, or "change your mind about". Although you may be unedcated on the idea of conception does not mean it does not happen to you. Whether your 15 or 50 you carry sperm that will inpregnate your unprotected girlfriend.

Please test, find out if she is, and take the proper steps from there.