Polymenorrhea or bleeding from vagina more than once a month could be due to several causes such fibroids, adenomyosis, endometriosis, uterine polyps, hormonal imbalance, thyroid problems and bleeding disorders. It could also be due to an IUD implant if you have one or due to oral contraceptive pills. It can also be a part of severe pelvic inflammatory disorder. STDs like Chlamydia and gonorrhea too can cause this.
You should consult a gynecologist to get an evaluation done.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.