Any have a similar situation?

Instead of my period I had 4 days of brown spotting, which is already abnormal for me, sometimes I have one day of brown spotting then full blown AF, well I had the 4 days of spotting and then 1/2 of one day of big clots and blood and today absolutely nothing, not even spotting. Tests have been negative but I have two children already and something is off. Has anyone had this situation and actually be pregnant??