If i ejaculate inside my girlfriend 10 days before her period what are the chances of her getting pregnant. (it was only a little not a full load)?

Certainly possible: Anytime one engages in unprotected intercourse, pregnancy is possible. If one engages in sex mid cycle, then it is technically more likely since it is in proximity to the time she would ovulate. However, pregnancy resulting from a single sexual encounter can depend on many factors such as male sperm count, her cycle length etc.