That's happened to me twice. It's quite a shock, isn't it.

One of the times was with my dove, Flutters. She was 4 years old before she laid an egg. That was last summer and she hasn't laid any since. It's hard to break a habbit so I usually still refer to her as a boy.

The other time was with my lovebird, Romi, who used to be Romeo. I had a pair of rescued lovebirds named Romeo and Juliet. Juliet had laid eggs several times, but Romeo never had. Juliet died leaving Romeo by himself. Not too long after Juliet died (a few weeks, if I remember correctly) I found Romeo sitting on an egg. It just happed to be April Fool's day and I was certain that my husband was playing a joke on me. It took him awhile to convince me that he wasn't. She's laid several eggs since then.