3yr old says head hurts but a few min later she says it doesn't, happened last two days and diff spot each time, same with tummy and legs on and off?

Then don't worry: With youngsters, they are learning what hurting is, when it is important, and how to deal with it. Watch for repeated complaints in same spot over a couple/few hours, as then is likely an issue (like headache x 3...Or more), versus here-there-anywhere over day, particularly if no change in behavior / eating habits / activity level.