ok... so when we have successful fertilization, both of them should come out of the hut and the woman should be carrying a baby right? they don't "show" pregnant do they?
Just watch the population number. If you have 14 people, watch the number 14 and start mating them. The moment she becomes pregnant, the number jumps to 15.
They do not actually have to enter the hut for her to become pregnant. The fertilization takes place when you mate them. What I do is repeatedly mate them until I notice the population number went up by one, or I notice at the bottom it says she does not want to mate anymore because she is "Nursing a Baby!"
Note they become sterile when your population limit is reached. If your population limit is say, 30, and your population is 30, no one else can become pregnant until your population limit goes up. When your population limit is reached is the best time to mate them like crazy to create Master Parents as they will never get pregnant and can be mated over and over and over .. sort of like Ft. Lauderdale during spring break.