My first cyst was on the right side next to the tailbone, the next one I've just dealt with is on the left side in the exact same spot as the right. Since I was a kid though I've had one on the top of my head and the back of my neck.
I take that back. Yes, the abscess was on the left side, and that is where it always flares up. But the cyst, I believe, is smack-dab center right below my tailbone. I notice if I push on it with some moderate pressure it's always tender. Like a deep ache feeling.