In Brad's Erotic Week Brad engages in sexual activities where he, up until now, doesn't use protection.
One can now speculate, which of the women might be taking the pill etc., but honestly it makes sense for most of them not to be on any kind of protection.
We know that most are not in a current or ending relationship with men, some prefer women anyway and for sleeping with random guys from a club or blind date, condoms would also work fine.
In Emily's case there are numerous possibilities as well, why she wouldn't take any protection:
Maybe she already wanted a child and it never worked; her ex is by chance or operation sterile; they used other protections; list goes on...
All this leads me to think, that it might be highly likely for Brad to conceive a child on some of this games many paths, if he "finishes" in certain places.
Personally this is something I would very much like to see on a few paths, where Brad manages to enter a permanent relationship with 1 or more women (getting greedy), since it can provide a very new level of eroticism and intimacy.
Now I am waiting for Wolfschadowe to rush around the corner and destroy those hopes!
