If it's new, definitely get it checked out by the vet

We took in a stray " Mr Robbie the Stretch " mid january this year, and when He finally
gained the trust from me ( mainly because I was feeding him

) I discovered
while petting him that he had a strange protruding lump on his rib cage

vet
checked him over and concluded that it was an old injury that has healed, feels weird
petting him as it sticks out a fair bit, feels like the tip of a finger

but it too doesn't bother him

best to get him checked out anyway