Ive been getting stomach pains and feeling sick for about a week

Hello! You don't really provide a thorough  description of your symptoms, so I can't really tell you what the cause exactly  is. Stomach pain can be caused by a variety of reasons including these: the flu ( flu bug attacks the stomach), nervousness, skipping meals or eating greasy  junk food, a dramatic change in your diet, taking any kind of pills ( are you taking any meds?) Since you feel tired, it can be the beginning of the flu or perhaps a sinus infection. I'm not a doctor, but you should drink plenty of water and then see a doctor asap. I hope this helps!