Once you get a BFP, can you pass on sonograms?


I'm doing <a href="https://glowing.com/glow-fertility-program">IVF</a> and am hoping not to have to do ultrasounds if/when I get a BFP (until about 22 weeks that is). Has anyone declined ultrasounds once you were pregnant? Or have information/research on why I should absolutely get ultrasounds?