I have always had a normal period. i missed my period in july it was suppose to be the 29th and i finally got it August 6th it was heavey compared to all my other periods and it lasted almost a full 8 days when it is usually just 3/4 days. i was suppose to get my period yesterday and havent i don't even feel like i'm going to start. i have took 3 pregnancy test after my 1st missed period and all 3 said negative. i have been very tired, moody, and felt sick or have got sick. i am not under any stress so what can it be?