Mucocele??Please Help

Hey!!!
i'm so glad I've found this site as I've been worrying about the small lump i found on my lower lip for ages.I first discovered it about 6 months ago and decided if it got bigger I would go and get it checked out...well it didnt get bigger so I just stressed about it for months.I am a medium smoker and so all I could think of was mouth cancer although i figured it was probably some kind of cyst or something.Anyway after looking online today i figured it is probably a ''mucocele''........here's my description:

Quite dark blue looking
Seems to swell up slightly then goes down
Feels like a hard bit of flesh
About 1 cm in length
Slightly raised althought it does seem to almost heal but then comes back
Painless
Located on my left lower lip
less prominent 1st thing on a morning,but seemd to swell up slightly during day.

Ok and this is embarrasing - Swells up like crazy after Oral Sex(man on woman - I have since stopped lol)....

Does this sound like a Mucocele or something similar?

YOUR INPUT WOULD BE SO APPRECIATED!!!!

I know I should have had it looked at but I was totally sh***** myself THANKS - Rich