Am I pregnant?!

I was supposed to start my period two days ago. I just now started to get light brown discharge, but no period. I took a test three days ago and it said negative. I have sore breasts, some here and there nausea, and fatigue. Is this implantation bleeding? Or could it just be the start of my period? My periods have never started out like this before. It’s always light pink, not brown. And usually comes like clockwork. Just thought I’d get the opinions of you lovely ladies! 😊

Thanks y’all!