It's not the egg song/escort call. One of my hens makes noises when laying sometimes (not exactly like that). It could just be because of stress or pain. I'd say give her a day and see what happens.
She doesn't really fell like she has anything in her anymore (although I'm no expert) and is still active. Is it possible she already laid the egg? Is there a way for me to know if she has? Will she be fine if I give her the calcium citrate and lubricate the vent even if she is fine by now?