My gf got an inplant thing in her arm to stop gettin pregnant but she says afyer we have sex the semen doesn't come out for days! Normal? Good/bad?

Probably normal... Probably normal...But she should ask her doctor the next time she visits. The implant contains a type of progestin, a hormone that affects the mucus in the vagina and cervix, and this can make it seem like the semen doesn't come out quickly. Plus normal ejaculate becomes liquid quickly, so it may seem like it "disappears" in the mucus of the vagina, especially if the ejaculate volume is small.