my cat within the last week or two had a fairly large bump come up on his side. he is roughly 4-5 months old. hes been taken to the vet and given all his shots. tested for feline leukemia and didnt have it. when we took him to the vet they took a sample from the lump but said the results were inconclusive and they couldnt see anything wrong with it.they told us to wait 3 weeks and if it doesnt go away or if it gets bigger bring him back. they thought it may of been a reaction from his last shots which were 3 weeks prior to the last visit. about a week or two before the bump showed up. it is a hard bump not attached below the skin as you can pull it away. it doesnt appear to hurt him or bother him at all. its almost oval shaped and about the size of two dimes placed side by side. hes still a kitten so it scares me i was just wondering if anyone had any advice or thoughts as to what it could be/ what i should do.