Spotting before period?

So my period was due Monday. I am not always super regular or on time however yesterday early morning I checked my cervix position which was low and had a bit of red blood on. I checked about half an hour later and still a bit of blood. I had some brief cramps like I was going to come on but went after about a minute. I had discharge that was slightly brownish/yellow for a few days before. Now this morning my cervix has gone back up and no spotting. I took a pregnancy test on Sunday and it was negative. Anyone had this before?