Hello,
Frequent bleeding with shortened cycles (Polymenorrhoea) is commonly seen in young girls and premenopausal women. Exact cause is often not known but disturbance of hormonal balance leading to ovarian hyperactivity results in shortening of normal cycles and sometimes excessive bleeding (menorrhagia). Usual treatment is cyclic hormonal pills which your doctor has been prescribing you.
STDs can lead to Polymenorrhoea by effecting uterus and other pelvic organs causing pelvic inflammatory disease (PID). As your STD tests returned negative other causes must be explored. Presence of fibroids in uterus and Endometriosis (abnormal uterine tissue outside the uterus which can cause bleeding ) can also shorten the cycles. Both are common in females of child bearing age. Ultrasound examination will be useful to identify any such uterine abnormality. PCOD (polycystic ovarian disease) can cause abnormal cycles although more often missing cycles. A hormonal assay of FSH, LH, estrogen and progesterone along with ultrasound will be helpful in ruling out PCOD. If still unable to determine the cause, laparoscopy can be done followed by tissue biopsy. In the mean time iron supplements can be taken as frequent blood loss may lead to anemia.
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