Ask or donate. 1) ask your doctor to check you blood for typing. It is a simple blood test 2) donate blood to the american red cross. They will also check your blood type there.
Blood test. Unless your doctor has a reason to order a blood type and screen (such as when you need a transfusion), the only way to find your blood type would be to donate blood. In the process, your blood will be tested and you can find out your blood type. Plus, you will be helping someone with a serious need!