plasma donation

been back donating plasma for the past week and a half or so and every thing has been going great except I have been having some pretty uncomfortable stomach aches that come on about an hour or two after the donation and last for a couple hours. I will plan on talking to them next time I go into donate (maybe wed or thurs?) hopefully this isnt something that would defer me from donating but I dont know if I would even want to donate if I keep getting the stomach aches. I suppose it is time to start looking for a real job...