Hi thanks for your question.
The bump which your mentioning on your labia minora
is most probably a Bartholin
cyst.Bartholin glands are normally present in vagina and produce screations for lunrication of vagina.When their duct of bartholin gland get blocked it lead to formation of bartholin cyst.It is benign cyst
there is nothing to worry,in case it gives trouble get it removed by gynaecologist.
Hope this answers your question.