What Causes Bleeding After Sex Post Hysterectomy?

I am 43 yrs old and had total robot assisted hysterectomy 9 mos ago for uterine polyps,failed ablation. Had hardly any bleeding afterwards and no bleeding since until tonight. I had alot of bright red bleeding after sex. No pain, no irritation. Just bright red bleeding. Some probably wouldn't consider it "alot" but for having had a hysterectomy, I would think any bleeding could be an indication of some sort of problem. How normal is this?