Article in English: If your doctor doesn't have your type on file, then you can also ask to get a blood test done. Call or visit your doctor's office and ask for a blood test to determine your blood type. Try saying something like, "I want to find out what my blood type is. Would it be possible for the doctor to order a blood test to check my blood type?" If you don't have a primary care physician, then you can have a blood test done at a health clinic. Just visit a local health clinic and ask them to test your blood type. You may want to call ahead first to see if this is something that the health clinic offers. This is an easy way to determine your blood type and help other people, all at once! Find a local donation center or wait until your school, church or community center hosts a blood drive. When you go in, ask the staff if they can tell you your blood type. Your blood is typically not tested right away, so it can take up to a few weeks for them to mail or call you with the result. Blood service centers usually provide people with free resources for getting their blood tested and finding out their type. In Canada, go to Canada's official blood website. Find out where the next "What's Your Type?" event is taking place.  These are regular promotional events hosted in the community by Canadian Blood Services.  Your results are instant and you will find out how common or rare your blood type is, who you can receive from, and who you can donate to.  You will learn both your ABO blood group, as well as your positive or negative Rhesus factor.

Summary in Chinese:
请医生验血。 前往卫生所或健康中心。 献血 前往你所在国家的血液中心。