While working out i all the sudden felt a super sharp pain in my lower abdominal, close to my hip bone. what could it be?

Pulled Muscle: When trying to sort out the different causes of abdominal pain, we try to separate out those that arise from the abdominal wall (which tends to be of muscular origin) vs. Those that are from organs within the abdominal cavity. Since your pain occurred with activity, it's likely the former. Furthermore, the oblique muscles insert onto the hip bone. Of course, it's best to actually see a doctor.

Many causes: The pain could be result of a local tendinitis or muscle strain such as the rectus or the obliques. In addition hip joint pathology and sometimes referred pain form the back may be the source. A hernia whether inguinal or sports may need to be considered. The abdominal organs can also be the source of this pain. If symptoms persist then a proper evaluation by a doctor can help with diagnosis.