Chances of getting pregnant?

I think when the game first released, regular woohoo had a small percentage. However, it was quickly patched out. The problem is, even if you have it set to a .01% chance of happening, the number of woohoos that happen between all players in a day is so high that even just a .01% chance would make so many accident babies. And most players would not want an accident baby.

For try for a baby, I think I read somewhere that young adults have a higher chance of getting pregnant then adults. But either way, try for a baby has a pretty high percentage.