As a SAHP you may or may not be entitled to child benefit depending on your OH's income.
However, that aside you still need to fill in the CB application form to get NI credits (carers and the unemployed, unable to work get these and so can SAHP's).
I am sitting here sorting out my future and looking at my state pension. You need 10 full years NI contributions to get ANY state pension. If you are a SAHP and not registered for CB you will lose these years. If you are a SAHP on or off for e.g. 5 years you can get NI contributions for this.
Please don't miss out on this. My state pension is a mess because I worked, then worked overseas for years, then was a SAHM here for 5 years and didn't register for a couple of years because I thought I was just not entitle to CB due to our joint income. I will probably have to pay up a lump sum, which I am OK with, but I've been very ignorant about this.
Please educate yourself on this and get registered if you are not.
Basically, if you do not have 10 years of NI contributions you get no state pension. If you have 10 years + you get £4.80 a week for every year you have contributed.
This is a really good link:Here