I av a solid purple sore and itchy lump on mons pubis.not been sexually active for 2 years. never had sti wat could it be been there for months?

Possible cyst: What you are describing could be a cyst, hemangioma, or less likely skin cancer. Hard to say without a photo. It is not an STI, but you should still see your doctor to get a positive ID on what it is. Ingrown hairs are common in that area, but usually are not purple. Moles/nevi can appear anywhere, and you may have developed one there, but it shouldn't itch. Best to have it checked out!