Advice on bump on dog's nose bridge

My dog is a Maltese Shih Tzu mix, he is 9 years old. I noticed this bump a few weeks ago but it was slightly smaller. He has gotten bumps before and in that same spot too and they've gone away with time and the vets had checked him out and said that he was fine at those times. But this time the bump seems slightly bigger, it could just be my anixety. Even now the bump seems to get smaller a little when we aren't inspecting it (applying a warm towel to it). He is not in any pain, and still acts the same. We are going to try to make an appointment soon. Thank you for any help or advice.

Update: The bump feels and looks smaller. It looks less red/pink

Hello and thankyou for the photos.  I'm afraid that I can't tell you what a lump is from its  appearance; it's not the outward look that is important, but the cellular structure that makes it up - and thats too small to see from the outside.  For example, this could be an encysted hair follicle, or a severe inflammatory reaction to a demodex mite or some foreign body, but it could also be a benign slow-growing tumour or it could be a melanoma.  None of these things would be obviously painful in most patients and all of them might shrink or grow a little.  We would reccommend taking this lump to show the vet because some of the options carry a poor prognisis and those in particular carry a better prognosis if seen early.  Wishing you and your boy the best of luck.