I had a problem come up at week 4 when I began my 1 3/8" dilator that actually was frustrating, but had a simple solution.
Put a very thick folded bath towel under your rear end, and have your knees up and flexed, and no pillow under your head. Yep, raise your tail and get the knees up as if you were going to wrap them around the hips of a well endowed lover. Try raising off the towel a bit and adjusting your angle that way, the muscle flexing in the area helps. This will take care of the first two inches problem. Gently tease the dilator into the opening, and twist it slightly to coax the vagina open, go gently and back it up if it starts to hurt. When the hurt quits, start going in again.
Pounding the dilator in like its a railroad spike hurts like hell.
(I still have no idea what the term "dynamic dilation" means, it sounds too painful for me to bear.