What’s happening?

Hello! So I have ttc for about 3 months now and I thought this month was my month! My breasts were VERY sore more sore than usual before my period and I had cramps but on and off like one cramp a day. I was supposed to start my period on the 19th but ended up starting it on the 16th. However the bleeding is kinda weird, I do have lighter periods 3-4 days long but heavy enough to have to use tampons

The 16th I used two tampons as they didn’t get very full and slept without using a pad or anything then on the 17th I used nothing at all. I only see blood when I wipe and it’s a small amount like spotting . Today I wiped and it’s just brown blood. I thought it could be pregnancy but I took two tests today and both came back negative. Has anyone else experienced this? Could it be spotting or pregnancy symptoms?