am 22 year old lady,i live in Botswana,since i started my period 7 years ago,its nerva been normal,it usually comes after 35 to 38 days,but today its now 44 days bit i havent come yet,i usually experience lower abdorminal pains like period pains,and feel tired and sleepy.i went for a scan two months back,my left ovary is slightly larger but they could not rule out polycystic ovary,i did two pregnancy test from last week but its nagative,currently am on medication (doxycyclines)for my acne ,so i need to know weather its an implication of serious illness or its just my body change?