If you're 3 months behind you've got too much work.
Besides, if you do the jobs monthly how can you be 3 months behind?
I'm probably about a week late, but I've never taken any notice of whether I'm "behind" or not.
I get there when I get there.
If I turn up spot-on 4 weeks it feels early.
If everyone says to me "Where have you been?" then I'm obviously a bit behind.
But I rarely hear that.
Some people worry about this job too much.