At any time you could have gotten up and walked out, if you were truly as set on not having "bareback sex". Why didnt you?
And, if you were not old enough,mature enough, or in reasonable mental state to choose your partners wisely, why were you having sex?
If you are under such turmoil about this, why havent you acted sooner?
My first thought would have been to do something immediately, not wait 4 years.
This isnt a matter of my personal opinion. Anyone, including law enforcement, would ask you these questions..they are very basic.