Hi,
Six months is generally too long for it to be a simple pimple.
It could be a benign growth, or a basal cell or squamous cancer. A determatologist can often tell just by examining it under magnification, or can biopsy if s/he feels that is warranted.
Please schedule an appointment with a dermatologist soon, If it is a benign finding you will immediately have peace of mind, and if it is anything else, early treatment is important.
Best wishes...
I agree with bluebutterfly2222 that 6 months is too long to be a pimple.
I had what I thought was a pimple off to the side of my right cheek for months (did the no-no of trying to pop it to no avail). It was pinkish till one day when I was visiting someone in the Twin Cities, I woke up in the morning & looked in the mirror to my horror, it had turned black. I figured I wouldn't say anything & hope no one noticed, but they did. Everyone said to see a dermatolgist when I returned...I said yes to humor them, but intendd on letting it slide, till I saw it wasn't changing back.
I did schedule an appt. & the Dermatologist cut it off right away & sent it off to lab...came back as a basil cell cancer. He did an in office removal of the area including a larger area around just to be sure to get a clean sweep.
I wish I had gone sooner before it turned but am glad I did go when I did as it would have continued to grow in size....not real fast, but still not improving anything.
Best wishes for resolution.