arms and legs always moving

[emmas]

I've read that arms and legs always moving is a sign of cp. My son is 6 months old and I've observed this behavior. Can someone please be more specific? How much movement is considered normal for a baby and how much is considered abnormal? This is my first baby so I have nothing to compare. I have an appointment with a neurologist because of my son's gross development skills (very delayed). Please respond. Thank you.