Anyone on tamoxifen and mirena coil-to thin endometrium lining?

Hello

Is anyone on this treatment combination. This has been suggested to me as I have thickened endometrium, biopsy negative. I had breast cancer 5 years, with chemo and radiotherapy. Periods resumed after 9 months later. I’ve been on Zoladex, 2 years of monthly injection and 2 years of 3 monthly injections since. My other options are orphrectomy-dont want more surgery at the moment or more Zoladex with letrozole, which I worry will give me too many side effects. 
Ive spoke to oncologist about risk of further breast cancer and mirena but he says this counteracted by the tamoxifen. Is there a anyone out there on this, I want to know about side effects s and breast cancer recurrence. 

Thanks Smash