Is this lump something to worry about?

Found a small lump on my dogs side yesterday. Its about the size of a pea, moveable, and doesnt seem to bother him when I touch it.

Vet appointment isnt until next week. Should I be worried or is this probably a fatty lipoma? Hes 2 years old mutt.

Just looking for some reassurance (or reality check) while I wait for the vet.