My cockateils behaviour

Question
My cockateil (Betty) is acting strangly at times, she puts her body in a horizontal position and ducks her head down while she paces on her perch and makes  
unusual noises. These noises she makes are unlike any of her other whistles and sounds. Betty doesn't talk at all so I know she isnt trying to talk. It sounds more like a clucking sound......
If you can think of anything this behaviour could possibly mean - will be appreciated.

Answer
How old is Betty?  Does she spread her wings when she puts her body into this horizontal position?  If she does, she is letting yuou know that she is getting ready to lay eggs, if she hasn't laid any yet.
If the noises that she is making sound like she is in pain, then she is going through "labor pains".  She will probably lay 4 eggs within the next wek or so, just let her sit on them.  Even though they are not furtile, her "mothering instinct" will take over and she will sit on them for a few weeks.  After a few weeks, she will realize that they will not hatch and she will quit sitting on them.  That is when it is safe to take the eggs out and throw them away.  If you do not let her sit on the eggs, she may continue to lay eggs, which can be very dangerous for her.
After she lays her egge, she will also continue with her strange behavior, she is letting the world know that she is a new mommy.  She will return back to her normal self after her eggs are laid and she sits on them for awhile.

Good luck and God Bless.