New To Site--question about a small lump?

Hello, I know there is a place on this site to introduce myself . . . and I will! I do have a pressing question/concern, though, immediately. I have just adopted Sarah, a seven year old purebread golden retriever. She is perfect in every way. However, I did just find a lump on her belly. I know it could be bad, or it could be a benign cyst or a lipoma. Could anyone tell me how common it is for Goldens to get lipomas? And, what does one typically feel like? Hers is contained to one spot, it's about the diameter of maybe a quarter, and it is soft and squishy--I can move it, if that makes sense. This worries me, as I just lost a dog three months ago after a year fight with lymphoma, but I don't want to jump to conclusions. She does have an appointment on Monday to get this checked out.
Thanks!
Leisa