Is there any way for someone under 18 to find out their blood type?

because my doctor refuses to tell me what it is.
Answer:
You could donate blood. The Red Cross should be able to tell you. I did this when I was in high school (not yet 18) and found out my blood type that way.

Uh, why won't your doctor tell you? Did you tell her/him that you were going to do something weird once you found out?

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Its on your birth certificate, but its strange that your doctor wont let you know what yours is.. do you know why?

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