brown bleeding

Good evening everyone.
For the past 4 days, I've usually had brown blood mixed with some mucus during wiping during the day. Could this already be the start of my period? Normally, my expected period date is tomorrow. Has anyone else had a longer period of this kind of bleeding and still gotten their period? I'm driving myself crazy with hope and I'm afraid a pregnancy test will just bring disappointment again. I also called the gynecologist on Tuesday and she said it would be my regular cycle. But now, on the 4th day, I still haven't gotten my period. Has anyone had the same experience?