I have a knot on my lower right back about the size of the end of my pinky finger. Had it for awhile, should I get it checked out or is this typical?

Yes. I don't think it will be anyting but without an examine you will not have peace of mind to let it go.
Knot. I would get it checked out. This could be a lot of things. Some of these need treatment right away, others may resolve on their own.