Well, that's hard to answer without some more info. Here's a couple questions that might help us figure it out...
What are the water parameters?
How long have you had her, and what size tank is she in?
What exactly is she doing that's strange?
Have you recently added anything to her tank - new fish, chemicals, ect.?
Is she the only fish in the tank?
How long has she had the lump?
Unless she's been with or around a male, I don't think she should have eggs...
Once we get a little more info, we can work from there. And welcome to the forum. :D