what could it be?

Go to the ER or to a "med-stop" sooner. It cold be nearly anything from cancer or a cist to calcium deposits or a bug bite. But you need to get it looked at ASAP.

I just realized that after about 4 months of pain, the small little quarter size pain that I have right next to my spine, mid back, right near my kidneys is actually my middle spine out of place.

I've had my lower back & neck out of place before, but have never dealt with this. The pain comes and goes, pretty much depends upon how I move. I was totally stiff, but I started going to the gym & streching more. I thought it was just a muscle, tried to have my hubby rub it out- bad idea !!! But I was laying in bed last week, went to roll over, my upper body turned, lower body didn't & I heard this loud POP- It was right in that spot. Then it was the sore pain that you have after your back is adjusted. Kinda slipped back out the next day, but it doesn't seem as bad now. Just when I move wrong. Hopefully this helps ya !!

its very difficult to say without seeing it. you need someone to look closely at it for you. it could be some type of infection (which would make it red, warm to the touch and possibly swollen)

if you have a fever, and/or if there are any red streaks coming out of it i advise you to see a doc right away, could be cellulitis. if you touch it and it feels like a little balloon full of fluid, it could be a cyst. if its hard, it could be a boil, a carbuncle, an inflammed insect bite, many possibilities. if its an infection, hot salt soaks can help to draw it to the surface, but you really have to be careful about treating it without knowing what it is.

I would go to the ER tomorrow, or a clinic which is open on weekends.