What is happening?😂

ok so all my life my periods have been irregular but one constant thing is my periods are HEAVY. like im talking first day of my period ill wake up in the morning and stand up and feel a whole glob fall out. well i can’t count on missing my period being a symptom of pregnancy, sometimes i have 30 day cycles and sometimes its 45 day cycles. my last period was from march 7-11. well as of this past sunday i started bleeding like this ( the picture). It comes out a touch more than what’s on the toilet paper in the pic, but not enough to need even a panty liner. sometimes it’s this color, sometimes it’s a deep brown and maybe once a day it comes out a deep red. no clots, no tissue fragments. i don’t even have to wear a pad! i’ve never had a period like this within my 10 years of having a cycle. the only other symptom is say i have that is different is sore nipples and every now and then a sharp aching like pain goes throughout my boob. i took a pregnancy test this morning and it was negative. could this be implantation bleeding, or just a hormonal change in my body bc of my age? (im 20 btw). Has anyone ever experienced this?? is it possible im pregnant but tested to early?? what’s goin on???😂😂