Girlfriend may make me go donate blood with her... Im on test.

Two concerns... First of all would my blood get rejected for any reason? I don't have diseases but could they say my blood is uhm dirty from illegal substances or something. You guys know what I mean...

Secondly... Is walking into a government ran organization like the red cross and giving steroid filled blood, after filling out forms, the same as robbing a bank and using your own car and license plate for the getaway?