I Have A Oblong Lump That Has Increased In Size

I have a oblong lump that has increased in size over this past week. It is to the upper left just outside of my scrotum, right in the area where my inner leg rest against the area to the side of my scrotum. I had noticed a small pebble bump there awhile back but over this past week it has gotten to the size of a pecan shell. It is real hard along the top of skin but not so under, there is a slight redness at the top. It hurts when touched. Could you might give me an idea what this might be?
Thanks