Hi Nicole,
I had an early stage of breast cancer in 2019 and am now a mum to a 14mth old and pregnant with my second. I didn't go through chemotherapy so your experience in conceiving is likely to be different to mine. However, I was taking Tamoxifen and on Zoladex for 2-3 years prior to my pregnancy. I would have started trying for a baby earlier but my Oncologist encouraged me to complete 3 years of hormone therapy first. Basically I had to come off everything and wait until my periods returned to normal before I could get pregnant. During pregnancy I had a breast ultrasound instead of MRI. After pregnancy I chose not to breastfeed and went back on Tamoxifen for a while, but in the end I did not complete the 5 years of treatment as per my cancer treatment plan.
I hope this helps. Best of luck with it all!