hi sweet fairy
welcome to health care magic
your menstrual cycle is normal but duration is very short.women is healthy only if her cycle last for minimum 3 to 5 days.need not worry low menstrual bleeding may be due to low haemoglobin
get some tests done to confirm to underlying cause.
blood test-hormone test, ultrasound
of pelvis and thyroid
if every thing is normal than her fertility
will not be affected.