period is late, negative test, brown discharge?

Haruko

my period is almost 4 days late now. I have taken a test everyday up until this point and all have been negative. I was supposed to start Wednesday but it never came. I have been having light brown discharge in the days before my due period, up to this point. the discharge looks to have gotten a little darker brown now but still no cramps or regular period symptoms. what is going on? **background info** I'm no longer on hormonal birth control and have been off of it for a month or a little longer now. I am waiting to get my period to get an IUD. last month, my period started 5 days early (a Wednesday) and typically follows a 28 day cycle, or at least did on my birth control. I logged my period and <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> predicted it for this past Wednesday, though it hasn't come. On my normal schedule, I would start this coming Monday. Could this be why I haven't started yet?