Mia
I am sorry but PIP is not classed as a "work" benefit and therefore does not pay NI Credits.
You could apply for Carers Allowance or Carers Credit provided you are to provide 35 or 20 hours of care a week respectively to someone with a qualifying benefit, CA would also provide a weekly income. I'm assuming that being a carer would not conflict with your own conditions and limitations.
Or, you can apply for New Style ESA, you won't qualify for payment but as long as you are assessed as having Limited Capability for Work then you should receive Class 1 Credits.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
