Do you mean the gallery where you can replay most of the games H scenes? Simply click on the "Extras" Button on the title screen.
On PC the pregnancy scenes are on the same screen as the normal h scenes. Maybe you can't see them due to the limited screen size on mobile?
Try going to the extras menu. Tap on one of the girls that can get pregnant and on the screen with the list of h scenes scroll down / swipe up.
