Considering that you can turn off pregnancy content right away, I wouldn't expect too much to come of it until the very end of the game or else Cari has to render every scene with the potentially pregnant LI in multiple versions.
We can't really know it yet, but Alex seemed to be a sexually active women (at least that would fit her character, in my opinion), so she will likely be on the pill or knew that it wasn't dangerous day. I doubt she would take that risk just like that.
Of course everything in that regard can only be conjecture one way or the other at this point.