Blood blister?

​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Hey guys🙃 so ive had this thing next to my vagina for a fee months, it was my skin color but tonight my man went down on me and noticed its dark purple, any ideas on what it could be?