Anyone ever gotten a utrine polyp? What was the cause of it ?

I had one bcoz of side effect from <a href="https://glowing.com/glow-fertility-program">iui</a> pills, had surgery to remove n everything was good. Recently I had my period twice..doc did sonogram found out I had a cyst n one polyp. Took another sonogram a month ltr n cyst went away but polyp is still there.