I'm Almost 46 Years Old, Have Had 3 Children, Had

I'm almost 46 years old, have had 3 children, had rings on my tubes instead of tubal ligation when I was 27, and have had regular periods ever since. They would start regular on the first day, heavy on days 2 & 3 then taper off and be done by day 4 & 5. Always regular every 28 days. In August, it seemed heavier than normal but did eventually stop, and I was due for my next period on Sept 18. On the 26th, I thought I got it, it was heavy for like half a day then stopped...and it's been going on and off ever since. When I wipe, I'll see blood and kinda mucus too so I'll put on a pad, but then it will stop and start again. I recently started exercising after leading a very sedentary lifestlye. Could this be the problem or something else, like maybe perimenopause??