I go to the gym everyday yet put on weight, stomach pains, backache, exhausted a lot and strange stomach pain yet had a negative pregnancy test?

See a doctor: See a doctor so they can run a blood test about your hormones and different glands like adrenal and thyroid and blood count so they can identify if there is medical problem or not, then they can have a plan to take care of your symptoms. Stress could be a major factor. Are you under a lot of stress? See a doctor please.

Wt: Reducing weight is not just related to burning calories by exercising. You need to have a well balanced diet with the calories you are taking in less than the calories you are expending. Your diet may also be causing your gastric problems.