I Ate Something That Has Upset My Stomach. I Think

I ate something that has upset my stomach. I think it was a potatoe that was old and had a green tint to the "flesh" My stomach aches and I have nausea but I have been unable to induce vomitig, two glasses of warm salt water didn't help. Trying to start the gag reflex didn't either. Is there some other safe emetic I might try or should I just tough it out until things get better?