I am 46 years old and in perimenopausal stage.So far I did not experienced significant differences in my  menstrual cycle.They would come on time and Last 5 days with 2 days medium / heavy flow and no clots.However last month I had to take antiviral for my flu and after that experiencing differences in my menstrual flow.It came early last month then now after  gap of  35-40 days I bled for 11 days with 6-7 days heavy flow and  grapesize clots. Should I undergo sonography and some blood tests or this is normal in perimenopause?