Squirming baby

ivy_leaf85

So, my 2.5 week old sometimes does this thing while he's nursing where he starts kicking, pushing with his arms, twisting/ moving his head, sucking really hard and grunting. He seems frustrated and it can be quite painful for me. His latch is fine before these little fits he doesn't do it every time he nurses. Anyone else have a baby do anything like this? Any idea why he's doing it?