History of lower abdominal pain
may be due to involvement of pelvic organs.
In women Fibroid uterus is the most common cause.
Infection of the pelvic like Pelvic inflammatory disease
may also cause pain.Ultrasound
of the abdomen and pelvic will help to find the cause.
As for as fatigue and excessive sleep is concerned it may be due to anaemia.
Consult your Gynecologist.