What Causes A Lump At The Opening Of Vagina?

I need help .

i have bin sexually active for about 3 years now . the other day my boyfriend said he felt something mid sex , not so far in to my vag but it wasnt on my vaginal wall it was just there . so i decided to check for myself to better understand what he was talking about and he was right . i have NO clue what this could be but im really worried. It feels like skin and theres a little lump or ball on the end ..

any ideas? :(

I went on to other sites but i couldn'd find an answer .

Please help!