Hold the eggs gently near a bright light. If you can clearly see a dark spot surrounded by blood vessels, the egg is fertile. The incubation period for Lovebirds is 21 to 26 days. Once the chicks hatch , make sure to provide a lot of good foods for the parents. They will be feeding the chicks, and should have corn, egg, greens, fruit and other foods available at all times.
Fresh water is very important also, so be sure to replace their water often.
Be sure to check that all the babies are being fed. Occasionally, you may have to handfeed a baby immediately. If the parents are feeding the babies properly, should continue to check them periodically anyway. If you don't pull them, the parents will kick the babies out of the nest at 5 to 6 weeks, and they should be eating on their own by then. The male Lovebird helps teach his chicks to eat regular foods.