I gave blood on Sunday. I've been having headaches since then, probably just due to side effects from my already-normally-low blood pressure. I've given blood before and haven't usually had problems that last more than a day, so this is abnormal. 

I will resolve this to the subjective percentage of my normal health that I feel on Saturday at 11 AM. If greater than 100%, will resolve to YES. I currently feel around 70% but have been extremely sedentary compared to normal. I may try to exercise on Friday and/or Saturday depending on how I feel.