Hello - I'm afraid that I can't see what I want to see here, so I'll talk you through some options. A red bump in that place could be a polyp, a localised overgrowth of tissue that has been growing quietly on the inside for a while, and suddenly pops out. Also on the outside, it could be a cancerous or a non-cancerous
lump. The picture on my phone isn't good and besides which, I'd want to check in person, to rule out a puppy or infection, placenta or prolapse leaving the womb. Particularly in light of those latter options, but also because of the lining of the womb being on the outside, this does look like something that you might want to get triaged by an emergency vet. Even if it is definitely lump close to the outside, excessive licking can be problematic - lead to inflammation and perforation - so pain releif and a collar may be in order.