I had a 4.5 cm cyst and a 2.4 cm cyst after one of my IUI cys, and I was placed on bcps because it helps resolves the cysts faster. All I know is that when I went in for my next u/s 3 weeks later, the cysts were 100% gone!
I can't tell you about pg and cysts, but often you don't ovulate a cy with cysts because good follicles can't grow, and it can also delay AF and the start of the next cy. That isn't true with everyone, but I was told it could be an issue and was strongly encouraged to do 3 weeks of bcps, so I did. I debated trying naturally and hoping for a

that cy and that the cysts would be gone, but then I thought I'd be more disappointed if I had to sit out 2 cys.
Cysts should resolve naturally within a few weeks to a few months, so you may be just fine waiting it out!!