Vigina lump, need advise?

I have found a lump on the inside of the lip on my vigina near the top, it is a little bit bigger than a pea, it wasnt sore at first but is started to get sore and i have now found a red spot on the lump, it has got a little bigger now but has gone a little softer and feels more like a hard blister. It has only been there for 2 days, i did shave the other night (the night befroe the lump appeared) and dont know if it could be caused by this and maybe it is an ingrown hair but would there only be one lump and would it get bigger?? Anyone get any other ideas?? Thanks