I m 23 years. Since 2 period cycles I have been experiencing very light bleeding. My periods last fr 2-3 days. I got my periods when I was 14 and ever since it had been v irregular. However, since last 6 months my periods became very regular all by itself and the bleeding lasts fr 5 days. Then what is the reason for sudden short n light periods? Had a scan in sept 2015 that showed polycystic appearing ovaries (I have not taken any treatment fr that Till now) A blood test in august 2015 which showed v low levels of vit D n b12. Thyroid - normal. Taking supplements fr vitamin def. I will do any other reqd test. And I know a doc can give precise ans after a test is done. But I just read on the net that scanty n light periods often indicate major health prob. Is it true? Thank you.