bigdog1 wait

I cared for my severely disabled husband for 18 years whilst also working full time. eventually I had to reduce my hours to enable me to take him to appts each week . I was never entititled to any carers allowance or anything else due to my salary , but he got PIP/DLA. Obviously my NI contributions were reduced when i went part time . Can I claim any sort of NI crediits to be backdated to the period when i was caring for him? If so How ? I now find that despite working 38.5 years and never claiming any benefit apparently I havent paid enough to generate a full pension when I reach pension age in 5.5. years