Hello emilyo.  So sad about what has happened.  Sometimes I think our minds put a defence mechanism in place to shield us from such awful events; in your case the suddenness of what has happened - it dropped into your life suddenly and then took off like a steam train crashing (if that makes any sense).  It was all far too much and far too quickly.

I cannot really comment on the scans - like others on this forum I have no medical training but I hope the Nurses might pick this up and respond.  I know it does happen that scans do not pick up everything but beyond that I really cannot comment.  And possibly some of your anger over this might also be part of deflecting your shock at your mum's death.  I say "possibly" because I am no expert in such matters.

I hope your family stick together and talk to each other about your feelings.  You might also consider ringing Cruse Bereavement Care (Freefone 0808 808 1677) to help you make sense of what has happened; they are long-established and experienced.  They can help you straighten out things in your own mind.

Be kind to yourselves, both you and your dad.  You have had an awful shock.