Check your Biopsy results, Shae ..... if your diagnosis was ER/Pr+ ... that means your Breast Cancer was being 'fed' by Oestrogen & Progesterone (the hormones that are in HRT.)
This is why Hormone Suppressing meds (AIs) are suggested after surgery.
I was on HRT when I had my FIRST Mammogram 'call back'. It had made my breast VERY lumpy and they had difficulty reading the Mammogram. As a result of that experience, I stopped taking it.
About 10 years later, I was diagnosed with Breast Cancer. It was missed by BreastScreen NSW - & only picked up by my GP when she did a random 'boob check' on me & she felt it. (It was just months after the 'clear' BreastScreen mammogram.)
Ask your Oncs about it this week when you see them. Be guided by them
take care & all the best