All the AF signs but no spotting or bleeding? Huh?

I am expecting my AF today and have had all the signs it's coming 3 days ago sore nipples, yesterday feeling bloated and today horrid cramps but there is no bleeding? Usually when I get sore nipples I get the brown discharge then by the time I am dying from cramps I have my heavy AF... Anyone experience this before? My signs and symptoms have always been spot on so I am confused.