How do you stretch a new lip piercing?

from the day you get your lip piercing done, the back, flat part of the labret bar imbeds slightly into your lip, don't worry as long as the lip doesn't engulf the bar, because this is normal. as a...

it swells for about 2-4 days up to a week sometimes not at all depending on the person and how well you take care of it. sometimes it may spot bleed a little for the first 36 hours.

take it off your lip and put it on your ear, unless if it's too small.

yes, you can. as long as you keep your mouth clean.

I would go see your piercer. It could just be the formation of scar tissue or it may be a reaction to the jewelry/rejection.