good day,my last period was on the 16th march,i have a 23days regular circle.everything being equal,i was supposed to have my last period on the 8th but since then ,i didn,t have it till saturday 16 that i i have scanty black blood which according to me is very onusual of meses.very black in colour and not continious.its not flowing out,its only for instance like i go to stew ,and when i clean myself,i fit this very dark substance coming out of my private.on the 14th of april,,my doctor prescribe a pregnancy urine test wc was negative.so i am just stess up because i really need.......I am 31years old.weight 90kg and height 1.65.