Late Period

Hey, I'm currently on CD36. My cycles are usally between 29-30 days. The last time I had a long cycle of 39 days was 4 months after having my little boy (September 2022) Since having my little biy my periods have been heavier and more painfuli just assumed this is part and parcel of my body changing after pregnancy. I dont track ovualtion as such, my smart watch takes my temp and predicts ovualtion and periods. At what point would you go to the doctors? Ive taken pregnancy tests and they are negative. I feel like I have PMS but nothing. Any advise or anyone had something similar.