Hello. 4 Years Ago I Had Stage 1 Breast Cancer.

Hello. 4 years ago I had stage 1 breast cancer. The treatment was lumpectomy and radiation. I tried tomoxephen but had such difficulty I stopped taking it after about 8 months. I'd had regular periods until my surgery and then stopped having menstration. I've had a couple of uterus cancer scares but so far ok. I have suddenly had on two separate occasions blood spotting almost like menstration. This is almost 4 years after no menstration. My breasts are extremely tender. What could this mean...? Is it normal , common , or ?

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