Hi ! Most likely you had some food which possibly was contaminated. That is why you had stomach pain with headache caused by a possible low grade fever
, and the toilet little more as described by you. Food poisoning
is very common specially during the present climate of heat and rain specially if it has not been cooked or stored with special hygeinic conditions. I would suggest you to go to your family physician and take medicines if advised by him before it gets worse. Take care.