It is important to know where the bump is that you are talking about in order to figure out what it is.
If the bump is located in the region of the pubic hair above or around the genitals, then the likely possibilities would include folliculitis (an infection of the hair shafts), an ingrown hair, or a boil (related to ingrown hairs or folliculitis, but more swollen and enlarged). You could show the spot to your doctor
, who will be able to help you figure out what is going on and what, if anything should be done. Sometimes large boils need to be lanced in order to improve.
You certainly could have a cyst in this region to, as cysts can occur anywhere on the body and are generally benign and do not require treatment.
If the bump is within the labia themselves, then there are other possibilities. These include a Bartholin's cyst, which is a blockage of a normal gland found in this area. Sometimes these do need treatment, either by lancing or with antibiotics or other methods.
Again, the best thing to do would be to talk to your OB GYN or primary care doctor
, who can help you figure out what is going on.