Hi doctor,i have been on petogen for 8months and since I last went for the last shot on 27/06/2017 I didnt see my period for 3 months then saw them on the fourth month for seven days,since then I was supposed to see them on the 24/10/2017 but nothing till today,i have light headache,cramps on the side of my stomach,lot of appetite and last sunday I tested negative..what could be wrong?