It will happen until the batteries die or you reset it. To reset while you see the egg with wings, press the A (left) button and the C (right) button together and a new egg should appear. Press the middle button and choose reset and set the date, time, and your birthday. Then, wait for the egg to hatch. This takes about 1-5 minutes. Then, you should see what gender you get. Then, you can name the baby and take care of it. You will lose all your generations, points, souvenirs, items, and donations to the king. You can also press the reset button on the back to start a new tamagotchi. Use a pencil or a toothpick and don't poke it too hard. Then, do the same thing I showed you how to do. Good luck with the new baby!