Why do I have a blister like bump on lip after Mohs surgery for BCC just above lip line? (Photo)

BCC just above lip line. Blister like bump was present with the stitches and after stitches were removed. Never saw surgeon after surgery. Called office and nurse said to wait it out. Now at six weeks, saw regular dermatologist today. She asked me if I had had anything on my lip in this area, no, I did not. She didn't seem to know what this could be or caused from. Told me to wait a month and return to surgeon if not changed. I am comfortable with this. I rather go back sooner that later.