No, you cannot have babies, get pregnant, or engage in WooHoo in The Sims 3 on Xbox 360.
The Missing Mechanics
No Romance System: The deep romantic interaction tree (Flirt, Confess Attraction, WooHoo, Try for Baby) present in the PC version is entirely absent.
No Pregnancy: Female Sims cannot become pregnant. No baby bassinets, toddler stage, or inheritance mechanics exist.
Design Choice: EA simplified the console port significantly to fit memory constraints and target a broader, more casual console audience. The focus shifted to karma powers, direct control, and story-based "Karma" challenges.