Worried about my girlfriend being pregnant. I took the measures I could. What can I do, now?

All you can do is wait and see if she misses her period. If she does, then test. Just cause she doesn't feel strange, or isn't having any early pregnancy symptoms, does not mean that she isn't pregnant. But seeing as how this happened on the last day of her period, it's somewhat unlikely. Any day of the cycle, a woman can fall pregnant, but it's more probable when she is ovulating, and women don't normally ovulate while on their period. Also keep in mind, the younger a woman is, the more fertile she is. All you can do is pray that this works out your favor, but remember, babies are a blessing. Good luck to you.