Why no unplanned pregnancy?

I like I can Try for Baby in TS4 and I love the new take pregnancy test option but it would be nice to have the realism of an unplanned pregnancy for my sims. Unplanned pregnancies are a part of life so why not for TS4 sims? I think adding the option for accidental pregnancy via the woohoo interaction would add a lot of depth to the game. With that said, if a future expansion pack or update does allow this the need to put your kid up for adoption will also be needed or perhaps an option to make another family member or friend the foster parent, guardian or adoptive parent. Just a thought.