Hi, I Have 31 Day Cycle And I Am 29

Hi, i have 31 day cycle and i am 29 years olI. last year august I had endrometriosis and was given depo twice but on different intervals, i mean not eactly after three months straight. The doctor said that since I had history of stroke it would be best for me to get depo. After my last injection in March, i had my period back in July and was not normal cause I bled for 8 days. sometimes 2 days and very light, however, last month november my period return back to normal . This month i had unprotected sex and have not seen my period which was supposed to be due on the 24rd of this month. So far i have had cramping and thin watery discharge with no foul smell or itchiness. i took a hpt and it turned out negative. could something be wrong with me?