A Little HELP

So today was suppose to be day #1 of AF but she didnt show which unusual glow has the most accurate when it comes to telling me when it comes. So i took a test in the evening which came back as a BFN 😓. But the discharge i have now is still like a milky kind which i am not sure why. But i assumed that it was gonna come today because me and SO had BD last nite because we knew she was going to come, but when i cleaned myself afterwards i had like a brownish discharge that i cleaned out. Do you think i just tested at wrong time of a day or should i wait. Do u think i am in or out with a baby on the way. I need help this is the first time with all of this.... ALSO MAJOR CRAMPING AS IF AF IS GOING TO COME