Try to contact ur builder, explain what happened and ask they to check.
My friend's house has similar thing, it's caused by a rusted nail(the contractor put the drywall, the nail went through the pipe os water. after 7 years, the nail was rusted so the water leaks from therel.
But ur house is only three years old. so shouldn't be the same as my friend's.
if builder says no. then ask ur insurance to do it.
to fix it, u may need to cut the ceiling. but don't worry, they will fix it so nothing an be noticed.