43 yrs old & having 2 periods in 1 month:

It first started in May of 2020 then went back to normal in June - August - now it's September and I'm having 2 periods in 1 month just 10 days apart - it's not a heavy period - no painful cramps either - just normal. It began on my predicted ovulation day which is today Sept 23 ( reason I know it's my period is because I have soaked through a pad ) so it's not spotting. Just recently had my normal period for this month on Sept 9-13 ( 10 days ago ). I don't have PCOS or an infection/STD either ( been tested for everything ). Sept 14-23 started having mild diarrhea & headaches & then early morning the 23rd I saw light bright red blood when I wiped & now this afternoon it's more darker red & has filled a pad but no clots ( so far ). Could this possibly be Premenopause?