For the last few weeks i've had muscle twitching in my left thigh under my butt and stomach under my right rib cage. im not sure why, any suggestions?

See your doctor: In the absence of other symptoms, these are likely benign "fasciculations". Causes include dehydration, recent overexertion, abnormal electrolyte levels such as sodium, potassium, or calcium levels, increased stress levels/caffeine intake, etc. If the twitching is frequent, affects different muscles every time, or is associated with other symptoms like muscle cramps or weakness, see your doctor.