Hi, sorry if this is in the wrong place.

About, 3 years ago i developed a small lump above my tailbone. At first it was real small and at times it would start to weep after i had been in the shower. Then a few weeks later it grew to about the size of a small egg. It was real painful to touch/sit...do anything really. Anyways, i made an appointment with the Doc and on the day i was to see him, the lump (cyst) burst, to say it was horrid would be an understatement, it was full of a dark green, pungent puss. The doc gave me some Anti-biotic to help clear the infection and it appeared to work. However ever since it "cleared up" i have had a small lump in the exact same place. Sometimes you can barely tell it's there at all, but on other occasions it does grow to about the size of a small pea. It doesn't really hurt when i sit down, just kind of annoying at times. At the time, the Doc never suggested it was any kind of cyst and also mentioned nothing about any further treatments, he didn't really take a look at it either, he just went "Ugh, puss" and then gave me a fortnights worth of tablets.

Could this be a pilonidal cyst? I assumed Cysts just stayed there until it had had treatment, but this lump regularly changes size.

Thanks in advance for suggestions