Welcome to HealthcareMagic.
I guess such irregular periods
are very uncomfortable to you and so frequent periods can cause huge amount of blood loss and so anemia.
What you are having is called Poly menorrhagia
.This needs proper evaluation of your genital tract and hormone levels.as you have this since your puberty
, i advise you to get tested with a Gynecologist , Endocrinologist
for further review.