Lower, center abdomen pain? What could this be?

I'm 18 years old, female, and having pains in my direct center, lower abdomen, about two inches below my belly on. It worsens when I move, blow my nose, and try to p stool, and move in certain ways. I've had intestinal issues for around a week, having pain and difficulty ping stool. Not like constipation, it's just a bit harder to p. Is this my intestines, or something else? Could it be appendicitis? Should I seek medical attention? I'm a bit of a hypocondriac and appendicitis is current among my friends.