It's like Mother Nature is playing tricks on me..

Priscilla • 30 | Happily married👰🏻 | mommy to twin boys born 8/19/17 👶🏻👶🏻💙💙 | baby girl due 1/23/19 💖
I don't have my normal AF symptoms just some mild cramping my cycles are always 28 days and about a day or two before AF shows I always get brownish discharge (sorry tmi) but I haven't had that this cycle.. AF is only 1 day late but I had hope so I tested and bfn.. What gives?! Anyone else have a similar situation?! Any input would be greatly appreciated.. Thanks in advance