My blister / lump is on my inner-UPPER lip

Been about 3 weeks since I first noticed a reddish and painless bump on the inner part of my upper lip.

I feel the urge to bite it and if I do it is not painful.

I see a doctor in a few days and will hope to get referred to an oral specialist unless this is a simple and common problem.

In the past I've had a small blister on soft part of the roof om my mouth and it would "pop" and drain and eventually went away.

This is different and it seems to have gotten bigger in the last week or two.

Any opinions?