Well they can be undone to a degree and you can freeze your sperm (infertility or rather rather difficulties in getting pregnant due to scarring is a risk when having a surgical abortion btw.)
There are also injections you can get on top of condoms (which you should use anyway) - so the chances are pretty slim.
And of course you can always choose not to have sex with a woman you don't trust.
It's not irrelevant because I say it, it's because the child is there and it needs your support, regardless of what choices you had or didn't have.Just because you say its irrelevant doesn't make it irrelevant, it is very relevant when it becomes 100% a choice versus 0% choice.