Dear An: Let's start with the spotting first then move to the cramping pain second. Generally speaking there can be a number of causes for vaginal bleeding after hysterectomy:
1. If you had a supracervical hysterectomy (cervix left in place), there is still enough glandular tissue (same as uterine lining) lining the cervix to respond to estrogen from HRT, or ovaries left in place. This would not apply to you because the cervix was removed.
2. If you have known endometriosis, there are case reports in the literature of endo growing into the scar at the back of the vagina where the cervix was removed.
3. If one's ovaries are gone and there is no estrogen use, the vaginal tissues can become so thin and fragile that they can bleed. In this same scenario, a prolapsed urethra can cause spotting when the delicate tissues are rubbed by under wear.
4. If your surgery was for cancer there is a VERY remote chance that the bleeding is from a return of the cancer
5. My best GUESS would be some granulation tissue at the site of the scar in the back of the vagina. This is a more common problem sooner after surgery. It can be easily treated in the GYN's office with silver nitrate.
In terms of the cramping/pain you MIGHT have an ovarian cyst on the right side. Normal hormone production and ovarian cysts can continue to occur even without a uterus. Another possibility would be adhesions (filmy bands of scar tissue). Adhesions arise from surgeries,infections (eg PID, ruptured appendix, etc), or endometriosis.
Yes, I would recommend that you see your GYN to see if there is an obvious source of the spotting and pain. Having examined patients with concerns similar to yours I would have to say that sometimes we are never able to find out what prompted that isolated bleeding incident. An ultrasound can identify an ovarian cyst, if present.
Yours,
Jane