I messed up? Pregnant, RAI

Hi all, so I was diagnosed while postpartum last year in March. The spread was a bit aggressive so I had a TT, bilateral dissection, trachea scrape, parathyroid removal, yada yada… Anyway, I was set to begin RAI treatment in the next couple months as I’ve finally been able to ween my son from breastfeeding! But I just found out that I’m pregnant. I’m excited, but also terrified because of what my body had to endure the last pregnancy as tumors grew oddly fast. I have not told my family. Quite honestly freaking out, kicking myself in the butt, but also excited at the same time… My medical team is going to be mad. HELP! :/ Anyone else go through this…?