Any help and advice PLEASE

Okay so long story short I got what I was positive implantation bleeding that lasted two days. I got this spotting exactly a week before my period, I had nausea and pregnancy symptoms 3 days before the “spotting started”. I was 2 days late on my period with all the same pregnancy symptoms so I took a test and it came back negative. Than on day 3 of what would have been my period I started bleeding. Clots and very heavy flow. My period is usually only 6-7 days but I’m still having heaving bleeding? I have an “irregular cycle however I always know almost to the hour when I get my period and it’s always the same. Am I experiencing an early miscarriage? Any help or advice please I am desperate.