Second. The first one was more than a year ago but back then, everything was ok. I didnt have any problems. Dont know, must have forgot to drink enough.
Also, i have a pretty rare blood type (in germany): 0 rhes. neg.
My bad luck: With 0- i can give my blood to all the other people with different blood types but i can only receive blood from another person who has 0-. Nice.
Edit: Do you guys get money for your donation?