No, it will depend on different situations and a lot of it will be randomized, so in one playthrough depending on different stuff, someone will get knocked up, and in another they might not get knocked up even if you make the same exact choices you made previously. To simulate a somewhat "realistic" approach.
This and all the other mechanics will be explained to subscribers in details as they are being developed, but ultimately there will be some sort of tips, tutorials, or help screen implemented in the game some time in the future, explaining the different game mechanics because there is a lot. Cuz even though this is NOT a sandbox game, there is money, theft, crime, skills, jobs, a lot of different crap.
For now it doesn't matter what you do because it's not in it yet, but if everything goes to planned after the 0.2.0 update it will be fully functional.