If it is more besides your vagina entrance and your labia it could be that you have an infected Bartholin gland because they can be painful.
If you do a Google search for Bartholin glands your see detailed images of where they are. Try taking a bath in hot salt water but not so uncomfortable you can't sit in it.
Put between 4 to 5 inches of water in the bath so it's enough to cover your vagina where it's swollen and add quarter of a cup of salt dissolved in boiling water mix well in the bath water then sit in it for around 30 mins then dry off as normal.
If this doesn't help you will need to see your doctor who will probably specially drain it for you.
Hope this helps :)
I take it that you shave smooth seeing as you say you have been pulling out ingrowing hairs?
Where abouts exactly is this lump, how big is it, is it red sore or painful and how big is it?
It's a sebaceous cyst.
They are hard lumps just under the skin. They don't usually hurt unless infected (or you just keep squeezing it!) It's caused by a blockage in sebaceous gland (oil gland). This is due to bacteria. which does not mean you are disgusting or dirty. It could be from sweat after work out, intercourse, clothes rubbing, or scratching. They go away on their own, but if they are really affecting your daily life you can have them drained. You will likely experience this again. If it's infected, the dr will give you an antibiotic but this will not shrink it. The only way to shrink it is to have it drained or just leave it alone. Do not try to squeeze it. It will be painful and it will not likely pop because there is no head on it. It's not a pimple. It will only irritate it further. A hot compress or bath may help. It's more common than you think. It will be ok.
You can try to prevent this in the future by grooming, washing after workouts and intercourse and using personal wipes during menstruation, douche but they may still pop up from time to time. This has been my experience with them.
Have you ever had a bump just under the skin on your chin? It's kind of like that.
Hope this helps.
It's nice to know it's not just me.. lol
Just put honey on a pad and place it on the area.
Honey can draw out any pus and is also an antibiotic. Hopefully this will get rid of it.