My gf and i had proteced sex and pull out method she missed her period from a month ago, now she has dark brown spotting a month later? pregnant?

Possibly: Have her take a pregnancy test. The pull out method is not a good method of birth control. Typically a drop of semen is released prior to pulling out, and that is enough for women to get pregnant some of the time. It is better to use a reliable form of birth control - condoms, birth control pills, the depoprovera shot, implanon, iud.