Pelvic inflammatory disease, STIs, implantation bleeding,atrophic vaginitis, cervical or endometrial polyps, cervical erosions are few common
causes of bleeding in
between periods. Delayed
periods can be due to ovulation dysfunction, thyroid disorders, hormonal imbalances etc. Depending on your detailed symptoms and medical history your doctor may recommend a pelvic examination and other tests .Only after a detailed clinical evaluation the cause can be determined. Hope it really helps.