What Does A Lump Between Vagina And Inner Leg Indicate?

Hi, I am 19 years old and female and have a lump between my vagina and my inner leg. I have had a little bump there for a while but it didn t seem to get any bigger but yesterday I noticed it was much larger than before. It is somewhat of a thin line going straight across my bikini line. It doesn t hurt and feels as if I possibly pulled something, I do tend to walk a lot and also just got off my period. I am nervous to get it checked out because my mom has told me multiple times to not worry but I can t help it.