Vulvar mass ?

hi ladies! just looking for some opinions about this situation:

so i’m a teenager and don’t know much about this, but basically my period is about 3-4 days late. usually about 3 days before i get my period my breasts get a little bit sore, so i know when it’s coming, but they have been sore this time for about 2 weeks and still no period! they’re never usually too sore, but right now they are pretty terribly sore, and still no period. well before i got in the shower i noticed that the part which i guess is the “labia majora” (post research 🤣) is hugely swollen and it itches pretty bad, it hurts and burns when i walk, and it also feels a little bit hard to the touch i guess. just wondering if anyone has a clue as to what it may be and what i should do? thank you! :)