'Cannot confirm your identity'

I know my Govt Gateway ID and password and then it goes to page that says 'We cannot confirm your identity', which gives me 2 options: 'Try to confirm identity again' - which does nothing at all, and 'Contact HMRC' which is what i am now doing. I would like to check for NI gaps and maybe make extra contributions, but have not been able to get in to see my record. EVER!

Hi bobt,
We are sorry to hear you are having issues accessing your online account and regret any inconvenience caused.  
Unfortunately we do not have access to your records on this forum. For assistance you would need to contact the online helpdesk: 
Technical support with HMRC online services 
Unfortunately it is not possible to check individual records through this forum May I ask that you call our National Insurance Helpline on 0300 200 3500 (from the UK) or +44 191 203 7010 (from overseas) and they will be able to check your National Insurance account. 
Thank you.