I have had regular periods for years they're like clock work every 28 days starts 1st thing in the morning.  Last month my AF came as normal on 4/17 then this month when I was expecting it on 5/15 nothing.  I took an HPT on 5/17 and it was NEG then later that day I noticed a brown discharge when I wiped, later that night was a little more with a little bit of red in it and the next day and over night was brown and pink but not enough to fill a pantyline.  I was also extremly sick to my stomach all day yesterday and I don't normally get that during AF and the symptoms I normally do get during AF were not present at all this time.  I was preg once before but it took me being 2 months before I even had a faint positive but I was watching my cycle as much as I do now.  Any answers would be greatly appreciated.