Help!!!

So yesterday I was a 2 days late when I wiped there was really pink blood so I was like uggggh af came. Well later that night I went to change my pad and nothing was there. Then his morning when I woke up I wiped and really pink light blood again was on the TP so I put another pad in and its been 3 hours and there is nothing non the pad. Now I am super nauseous and having hot flashes. The only thing throwing me off is Saturday (when af was due) I took a test and it was negative. Could I still be pregnant even tho the day af was due I had a negative test?