every VISA being given, the moment you arrive Qatar, will only have a 30 days validity. You can extend it to a maximum of 90 days provided you did your medical at the medical commission. Since your already 2 days due, you are bound to pay the penalty of QR500( i think...or more) per day. You can't extend it if you haven't got your medical and blood group taken. i suggest you do start your medical first thing tomorrow because the result will be after 3 days (the earliest). AFter you receive the result, proceed to immigration, pay the penalty and pay for the extension fee.