Lump Whiskers - Bump on nose

I just noticed today that my 8wk old male guinea pig (who was born blind and we have his mother - was a surprise litter she ended up being pregnant when we bought her she had 4 pups we kept one of the females and then whiskers who is blind and he is in a separate cage til we can get him neutered).

I hold him all the time so this developed in the last 48 hours because I didn't notice it on Sunday when I was holding him. He has been trying to chew thru the cardboard we have up on the sides of his c&c cage not sure if he may have gotten a scratch or something from it.

From what I can tell it's just a small bump, it doesn't look dis colored or anything from what I can tell, he does have a small spot under his chin that looks like the hair is thinned out a little but he had a small scab there from his male litter mate who we recently rehomed this weekend so not sure if it's from that or not. Should I just keep an eye on this or is this something a vet should look at? He has been to the vet at 2wks old when we noticed he seemed to be having trouble seeing and getting around. I ended up hand feeding him from a few days old til about 6wks old but he is eating/drinking well now.

You can't really see the bump in the picture but it's right where the white stripe going up his nose the white hair on the side closest to the camera is a little tuffed up and out of place that's what made me notice.