by godhole » August 5th, 2012, 6:59 am
EMG is way ahead of ya! ;) He has several mpreg files, although the description is for one hour, and I don't know that you become a woman. (I'm not sure why the label for straight men, but this site doesn't do well with expected-user labels.) See if these fit the bill.
http://www.warpmymind.com/Files/158/QuickPregnancy.php
http://www.warpmymind.com/Files/2037/Quick-Pregnancy2.php
http://www.warpmymind.com/Files/100/Curse-Pregnancy.php
http://www.warpmymind.com/Files/207/TrigPregnancy.php
And in case you didn't mean _human_ baby...although this one does have the gender change written in.
http://www.warpmymind.com/Files/3110/Tentacle-Hentai-%28With-Impregnation%29.php