PERIOD OR WHAT

I am so confused, I got this around the time of my period and if its a period it'll be considered late. But i only got it for one day...then two days after I got brown mucous. I had protected sex with condoms a month ago. And the second day I missed my period I took a test and it was negative... So whats going on? I've been not having perfect cycles after bring sexually active. And no longj

period this month at all... Just this one day blood.