Choroid plexus cysts

i just had my 20 week ultrasound, they found 2 of these cysts on my babies brain. They said I'm very low risk of him having trisomy 18 and that they should resolve themselves so I have to go back in 6 weeks for another ultrasound. I'm really upset, my husband thinks I took what the Dr said he wrong way and I'm looking at it in the worst way when I shouldn't be. My 12 week scan said 1/10,000 for trisomy 18 so it's a low risk but I'm still scared shitless. Has anyone else had this with their baby??