I gave birth last year November 24 but breatfeed for one month so this year March I had unprotected sex and I use postpill after I saw my first menses that same month two times (early and late of March) so since then I didn't have sex but now last month I didn't see my menses only what I see is dropping of blood whereas in the absence of menses I am ovulating and tested negative for pregnancy test so why is my menses still missing