What Causes My Periods Lasts For 10 Days

I'm 50 years old with a history of functional ovarian cysts (had surgery to remove an 8 cm cyst a couple of years ago). I've had multiple follow up pelvic and transvaginal ultrasounds to follow what the gyne thinks is a calcification on my R ovary. I've had the Ca125 blood test (which I know is not very accurate) a couple of times and it has been pretty steady at 37 (which I've been told is just above normal which is 35). I know that (at my age) I'm likely perimenopausal, my periods have been regular about 28 days apart, 5-7 days long. This time my period is lasting 10 days, just wondering if this could be related to menopause, or should I see my doctor (I'm worried about ovarian Ca). Thanks.