Bleeding 4 years after a complete hysterectomy

I had a complete hysterectomy 4 years ago due to endo. I had 3 laser surgeries prior to that to laser it out. I had it on my urinary tract and bowels, in addition to ovaries and uterus and tubes. Now, all of a sudden, I started bleeding again after 4 years. I was on menest 1.25 for 3 years or so. I went off of them in mid-april. At the end of may, i started bleeding. I went to the doctor and he ordered 2 CT scans, one pelvic and one abdominal. both came back negative. I actually quit bleeding for about 2 weeks, then it started again. I will bleed one day, not bleed for 2 days, bleed for a day, etc... I have an appt. with a gyno in 3 weeks. I talked to the nurse who said it could be the fact i went off menest, and that i could be experiencing vaginal atrophy, or it could be endo again. I put myself back on menest, half of half (.03), so I will see what happens. She said that it could be dryness and I might need the estrogen to stop bleeding. Note, I do not have bleeding with intercourse. I do have cramping, like I am going to start a period, with back and leg pain. Strange since i have NO parts left. Do any of you have this same problem or have heard of it? I feel like the hysterectomy was a complete waste of time and money. I think I least I got four years off from periods, but this seems so unfair. :-(