My yeast infection has been gone for 3 days now, but the inner opening of my vagina is still swollen. Is this normal? Will it go away?

Maybe. If you mean that the yeast infection is gone because the symptoms of itching and discharge are gone, the swelling may still just be taking a little longer to resolve. You can put the yeast cream on your finger and apply it to the area. Can also try ice packs for 15 minutes at a time. If this doesn't resolve the swelling in another couple of days, see doctor to rule out other problems.
Usually resolves. It usually resolves with time and will improve. If it gets painful or increase in swelling, get it checked. Sometimes, bartholin gland can become obstructed that may require drainage.