Having irregular periods
is a sign of decreased ovulation which may or may not be related to approaching menopause. Specially if you don't have any menopausal symptoms like hot flushes. MOST important thing is that you are over 40 & any change in menstrual pattern at this age need investigations to rule out any problem with your womb and ovaries. That can be done by an ultrasound
scan. If this is normal then there are certain blood test
that can tell you if you are heading towards menopause. These if found normal then you don't need any medicine for periods they will come naturally. If you need to correct menstrual irregularity you may ask your Dr for Hormone Replacement Therapy
. If you are concerned about fertility
, you may go to a good fertility clinic. Best wishes.