Don't worry about it.
Maybe a portion of your hymen that is still attached? In any case if it causes you any type of discomfort get it checked out by a doctor.
And remember every girl looks different down there and some maybe have more skin then others. If it doesn't hurt or is uncomfortable (especially during sex) then it is probably not anything to worry about. But if it really bothers you go get a check up at your doctor to confirm that nothing is wrong.Why does my vagina have extra skin?
ifeelcrazy123 is right. It is most likely a remnant of your hymen and is perfectly normal.
The hymen doesn't fully go away in most women until they give birth vaginally.