What Causes Missed Menses With Slight Brown Discharge Once A Day?

i had a miscarriage last dec 2009 at 6 weeks (but no d& c procedure, as my OB told me that it was a complete abortion) and got my regular period february 23 2010... but last march 17 i strted to have a very slight brown dischrge once a day until march 27th... but up to now i haven't got my period which is cycle day 41 as of today... 3 days ago i tested and got a negative hpt... i don't have abdominal pains or any pregnancy symptoms, just being very sleepy for the past week up to this day... (i was diagnosed with a polycystic right ovary after my miscarriage... thanks for your time...mso confussing... i'm 34 y.o. and no children yet.. been trying for 6 months bfore i fell pregnant and had micarriage after...