Implantation bleeding or early period

My cycles range from 40 to 43 days. My last period was October 20th. Yesterday was cycle day 33 and I started bleeding. It was light, maroon red and thin no clots. Usually my periods on the first day are super bright with dark clots and heavy flow. It’s day 34 now and still bleeding but much lighter barely there when I wipe. Blood only shows on tissue if I insert it inside. My predicted ovulation day would have been November 15 or 16 or 17. Could be this implantation bleeding since it’s a week after ovulation and a week before my period?

Side note: I was pregnant in 2016 and I was getting a “period” every month until I was 5 months and had no idea I was pregnant!