First issue: Infertile Perk & Female Chastity
The infertile perk at the beginning of the game should prevent vaginal pregnancy however, without personally testing it, it may not prevent anal pregnancy if the anus (with Womb) option was also picked. Condoms are also an option and in the orginal options menu on the main screen before entering the game, there is an checkbox to turn off risky condoms, meaning that they will never fail.
The chastity belt is not an item currently available without the Debug menu. In debug there are two main chastity belts belonging to NNPCs, Vion and Artica. Both work the same, blocking the vagina but unaccessible through normal routes.
Second Issue: Vion Hacking Quest Chain
The Vion quest is notoriously difficult. Further down in the comments, a couple months ago, commentor Noblotus posted how to solve it.
"1. and only option after beginning -> help -> send -> probe -> send -> connect 3 (you need to click on the butten "NUMPAD" in the corner to wirte the 3) -> send -> help -> send -> unlock block (need to write manuel by clicking on "KEYBORD" in the corner) this is to skip the rest of this minigame. When you dont want to skip you can ignor this and follow this steps (not necessary for anything) -> unlock -> send -> monitor (remamber the green numbers in [] -> send -> strscan -> lock for the rigth grenn numbers in [] -> unlock (word behind the grenn numbers)"
Essentially: Enter Hacking Scene >> Help >> Send >> Probe >> Send >> Connect "3" >> Send >> Unlock >> Monitor [Remember Green Numbers] >> Send >> Strscan >> [Look for matching green number strand] >> Unlock "Word behind matching Strscan"
... or to do the skip the mini game: Enter Hacking Scene >> Help >> Send >> Probe >> Send >> Connect "3" >> Send >> Unlock "Block"