its called a male contraceptive for a reason... there's no 100% guarantee that it will prevent you from getting her pregnant but its going to make it a lot fucking harder for it to happen! heres a link to get the best quality... https://sarms.forsale/product/s23/
don't know this answer yet. have not seen enough bloodwork to confirm.
my advice always is learn to pull out, i don't care what you are are on and don't care what she is on. and don't care if you use a rubber either, those break and slip too. take no chances. remember most kids were unplanned.