If it is fairly early in your game, the villagers may just be developing parenting skill. Have you tried several times? Also, if it is early, a message may come that reads 'the villager is too hungry for this'. This doesn't stop population increase but is a warning that you may not have enough food to sustain a larger population.

There is an exploit in the game, not truely a cheat, but you don't have to let the villagers go all the way to the hut. You can pause the game and put the two together several times in a row until the population number increases. If you try this it may help.