What Causes Lump Inside Vagina?

hi my age is 26 and i have had no previous medical problem i have recently noticed a lump just inside my vagina it was not sore at first but got quite sore over the week end i was going to my doctor on the monday but on the monday the pain was gone so i assumed it was gone but now it has inflamed again and i got my partner to look and he said the lump was bigger i think its an apsis can i buy anything in the pharmacy that might help thank you