Feeling confused 🤔😔

On Sept 2-4 I was suppose to get my period instead I got light brown discharge on tissue when I wiped I wasn't sure if that counted as my period, but I did. I've been having a little bit of nausea. On October 1st I was suppose to get my period again I'm late 3 days (not surprised because I'm either on time or a week late). I've been feeling a little bit of nausea, had the runs for a couple of days (usually only get the runs when I'm on my period)

n for the past few days I've been cramping a lot, and had a slight pink discharge n it went away. pregnancy test came out negative 😔 I'm confused has anybody had this and came out pregnant??? 🤔🤔