idk what to think...

so I had surgery last Thursday tumor removed...anyways right after surgery I threw up of course before they did procedure they tested me for pregnancy which is a negative... however my period is due thus week on the fourth my last period s

tarted on the 4th of Oct and are usually only 4 days with fourth day being dark old blood as I call it... anyways this week just Sunday I started bleeding I thought it was my period but When I woke up and went to change it pad wasn't as full as it usuly is but I wouldn't call it spotting...so I change my pad wipe...there's no blood and prepare for work.. at work I go to change pad again and this time it was a decent amount worth changing but very dark like my end of period blood... I change and get home from work there is about the size of a green grape on the pad mind u I changed my pad 7hrs ago... so when I chage it at home and wipe there was a bit of red blood and kinda looked like snot mixed like pus...but not a whole lot. Later I prepare for bed and wipe again no blood or pus or anything..I still change my pad..Now this morning when I change my pad there is very little blood and dark like end blood but not really even worth changing pad. Everyday since I've been from surgery I've felt nausea...and my poo patterns have changed.negative pregnancy test here posted I think and I'm really sleepy unusual for me and I'm a get up and go person...idk what to think. What is this?