budgie neck stretching- should I be concerned?

by ma
(washington)

My 7 year old parakeet has been stretching his neck out repeatedly and seems like he may be regurgitating a little when he does this. Some days he will stretch his neck out over and over for long periods of time, and every once in a while he will have a day where I don't see him engage in this behavior at all. Otherwise, he appears to be in good health, active with an unchanged appetitie and singing frequently. I am concerned because this is a new behavior that is not resloving and has been going on for about 4 weeks. Any idea why he might be doing this, or if I should be concerned?