NEED SOME ADVICE

So my period is 16 days late. I haven't had any of usual symptoms to hint that it's close and I'm starting to get worried. I'm 20 years old and I'm a virgin, so there is no chance I'm pregnant. I'm worried because of my family history. My mom had endometriosis when she was my age, and later on cancer. And My cousin has polycystic ovarian syndrome. Should I go to the docotor, or am I just over reacting?