This is definately not the end!
If you have 15 villagers, you have 1 hut. There are 2 more huts to go! If you try breeding again you should get "there is not enough housing". Look around the map for a construction symbol. This will be the site for your next hut. If the symbol doesn't appear, try exiting the game and re-entering. This seems to trigger that hotspot!
If you still don't get construction on a new hut, let us know.