Unemployment Benefit and a baja

Hello, this is a very interesting forum.
I live in Spain but worked in Gibraltar as an Engineer, my wife (married in Spain) worked as a Teacher in Benalmadena until the birth of our son, and as he will be 5 next year she will return to work in the same school next September. Our son will keep going to the local school in the village he knows and loves.
Despite the recent financial squeeze of poor exchange rates (I was paid in pounds) we had a normal average life.
However on August the 9th I had a motorcycle accident during the commute home, I have no memory of the events, a frantic search by my wife and friends found me in hospital at 3am, I was discharged at 6am with a fractured collar bone, and bruises to be proud of.
There was complications with the fracture, and 4 painful months later I now need surgery. Meanwhile the 6 week sick pay entitlement finished, holidays owed used up and with no return to work imminent I was made redundant.
I completed the paperwork on Gibraltar that allows me to sign on at the local INSS, it won't be within the 14 days as there is a huge backlog in Gib, but they tell me there is an agreement with Spain to waive the 14 day rule, we will see!

So now the question (after a long introduction) what happens when I try to 'sign on' whilst still under a baja from the Doctor? Do I tell them? will they know? or do I try to look healthy? I'm trying to avoid problems with the mortgage payments before my wife returns to work and I'm fixed

Thanks, Andy