I know I posted about this already but seriously, is being tired, and having an upset stomach a good enough reason to leave work early?

No. You have to be really sick, and I mean REALLY sick like stomach cramps are too bad to make you continue your work, only then you can go home earlier. I'm tired every day at work, if I would leave work for that I'd get fired one day... Have you heard about passionflower? I take one pill based upon that herb that helps me to prevent to get upset stomach due to stress, which I experience daily. Before I took it , my stomach always hurts, but now that I'm taking it, it hurts only when I ate something bad. And I can continue with my work. Tired? Get some coffee ;)