What is going on

its now been 12 days since expected AF was supposed to arrive. 6 days ago I started bleeding so I thought it was AF but I only bled for 1 day. 2 days later I had a link pink and brown discharge. I have not had any more bleeding since then, only some mucus discharge. The test I took 2 days ago was negative. Was the one day my AF for this cycle (very unusual for me) or could there still be a chance I’m pregnant and it’s just not showing up on a test yet?