If you follow "the rules", does it matter?
First off, I'll say, there are many aspects to this hobby that can make one afraid; like violence or disease. If anything scares you, you shouldn't be doing this hobby at all. That said, the repercussions of getting a provider pregnant can fall into that category of fears as well, but only if they find out who you truly are. These "rules" are mentioned around here for a reason, it's pretty basic stuff:
1) Burner Phones, a no brainer for this hobby.
2) Burner Wallets. Another no brainer. Never bring your actual wallet with you. No IDs or CC or debit. No wedding rings, name tags from your job at Best Buy or Alumni swag, anything that can trace back to you. Only the money you agreed to pay.
3) "Don't shit where you eat"; meaning, don't go for the provider who lives a few blocks from your house, whom you regularly see at the corner store offering back alley BJs. Go to another part of the Metro, or another city altogether.
4) Never park your car near the Incall, in case you're going to a condo and the building's CCTV gets a view of your car and license plate. Park a few blocks away.
5) DEPOSITS are a double-edge sword that can cut you if you're not careful. Never give a deposit to a provider who isn't vetted on any review site or well self-represented on social media or their own personal website. You can "trust" a top-shelf provider to be discreet, but for the random 'independant', 'new to the scene' girl asking for one. It's a risk, not only to lose your deposit money, but (depending how you go about it) it leaves a paper-trail back to you, in case the accusations and blackmail start flying about...
5) Don't be complacent, even a trusted ATF you've seen several times can suddenly turn toward the bad path of drugs, despair and desperation, then take you along with her. Stick to the above rules at all times...
...(and many more I cannot think of atm)
....the 'rules' are pretty common sense stuff, the point is to make sure nothing traces back to you. Do the deed, have your fun, and cut yourself clean from the relationship. Break the phone in half like another episode of 'Breaking Bad', and disappear. After all that's said, "Would you be on the hook?" Does it matter? You'll never see her (or them) again. Like other's here, I won't comment on actual legalities (not sure why we shouldn't, it's not like over 50% of the people in this country have baby-mama/daddy issues anyway, we should all be experts with or without the drama). But as a fellow pooner, Why wait for the headache to come for yourself? Just be smart in the first place.
On the flip side, providers themselves should know the score as well; know the occupational hazards of their craft, and leave "the choice" up to them, which would get you 'off the hook' as well.