Do i have a choice of whether i wish to receive a blood transfusion before a surgery if things were to go wrong and i lose lots of blood during????

Yes: You are free to refuse blood transfusions if you want. In this situation, your will pay for your bad decision with your life. Jehovah's Witnesses do this stuff. They die. Most surgeons would refuse to operate until you wise up. Blood component therapy has risks but today they are nothing compared to the risks of believing international scare stories and refusing needed health care.