Didn't breed, but laid an egg

[Tangential1]

My oldest gecko, Toon, laid an egg about a year ago. I found it while cleaning her tank. She has always been in a tank by herself, so I know she didn't breed. I think I've read somewhere that females will occasionally lay an egg even without mating. She was about 3 years old when she laid it. Is this something I need to be worried about, and how often can I expect this to happen?

 

[acpart]

I have found it to be relatively rare with leopard geckos. If you got one egg a year ago, I don't think you have to worry about finding too many more in the future, since normally a gecko would lay 2 eggs every 2 weeks or so.

Aliza