Hi, you are most likely in the perimenopausal stage where your menstrual cycle becomes irregular before you enter menopause. Is your bleeding currently very heavy? If you have been experiencing heavy bleeding for 3 weeks now and feeling tired, would advice you to see your doctor to make sure that you red blood count is not too low and also to check there is nothing else contributing to the prolonged heavy bleeding aside from hormonal imbalance.
Dr Sim Li Kun
(Dr Tan & Partners)