We are sorry to hear of your recent prolonged bleeding.
From a halachic standpoint, it is important to review the laws of stains, as by reviewing our site’s articles “Stains” and “Toilet Paper“. It is likely that you have been considering yourself niddah earlier than necessary.
On the medical front, given that this is a new development after eighteen months without difficulty, we do recommend discussing the matter with your physician. He or she may find it helpful to refer to the section of our website designed for healthcare professionals, Jewish Women’s Health.