HELP (TMI)

Hey ladies, so this isn’t about pregnancy. (I don’t think) BUT about a couple months ago I noticed a little bump down on the inside of my vagina lip. Sorry TMI. But it’s small and there’s only one and it hasn’t gotten any bigger or changed. It’s hard but tiny probably the size of a apple seed. No color to it. Anyone know what it might be?? (And no it’s not a STD, I’ve been with the same man for 4 years and have been tested early in our relationship)