Hello,
This can be due to menorrhagia. Sometimes it is associated with polymenorrhea(Frequent flow, cycles of ≤21 days)Causes of menorrhagia are Hypothyroidism, Endometrial proliferation or hyperplasia like ovarian tumor and polycystic ovarian disease,endometrial polyps and neoplasia,endometriosis,fibroids and uterine sarcomas.
In my opinion you need to get your pelvic examination done from your gynecologist along with investigations like complete blood count, thyroid function tests, PAP smear and ultrasound uterus.Once cause of menorrhagia is identified,treatment can be planned.
I hope it helps. Take care and regards.
forgot to say you most likely feel faint and dizzy becuz your losing so much blood.
you need to see ur DR clotting isn'nt good. please go and get checked out