I would at least wait 10 half lives of the AS you took to be sure that it has completely cleared your system (for something like a enanthate or cypionate, that is about 5 months. for deca, I would wait at least 18 months). Never give blood if you are on cycle or if you are not 100% certain it is no longer in your system. Severe complications to the recipient are possible.
Radar - I think the lifetime prohibition is due to the use of ANY injectable illegal drug because that is linked with higher AIDS infection risks. While the risk may be increased for druggies who share needles, someone who injects themselves using sterile needles and never shares needles is at no higher risk of AIDS infection than anyone else. Notice that this prohibition does not extend to diabetics who inject themselves daily with insulin. It is assumed that since their insulin and needles are provided to them sterile that they do not pose a risk.