I'm A 50 Year Old Male And About Two Weeks

I'm a 50 year old male and about two weeks back I noticed a lump in the anal area. The lump is the size of a large pea and hard and is on the ridged skin surrouding the anal opening. There is no bleeding in my stools or any pain while passing them. The lump is under the skin and there is no change in the colour of the skin versus the surrounding area. There are no other symptoms. I am extremely worried and I plan to see my doctor when I am back from offshore in two weeks time but I would just like to know anything that would help me to understand what it is.