My baby had a bright spot on her heart early on. Everything else was growing just fine on her though...therefore it was a single marker. I had a blood test done to check for Down syndrome and it came back negative. I'm 35 weeks pregnant now and it completely disappeared. DO NOT get an amnio done unless it is something that can cause a life or death situation to you or baby. Those things are way more risky and have a high chance of causing a miscarriage. Just wait it out. Your baby is most likely fine.
2 of my kids had those white spots show up in ultrasounds. Perfectly healthy babies.
I had one this pregnancy. I'm waiting on my due date because I'm huge, so I have to have a second growth scan next week. But I'm definitely 8 months prego lol. My baby's Cardiologist said he wished they wouldn't even tell moms to be about them (EIF) because if they are the only marker, then it's nothing to worry about. And sometimes it's just from the ultrasound machine. The Amnio is risky. I thought they we're suppose to send you to a Ped Cardiology to follow up, then offer the Amnio if it shows up again. I would ask for the NIPT blood test. It's safe and just a blood draw and will tell you the baby's sex. I wouldn't read too much on the internet because it will drive you crazy! My son is growing beautifully and healthy.
My baby too had a small white calcium deposit. It's common and goes away a few weeks to months after delivery. I was told though it can be a small marker for downs. Because of that I had further blood testing. My baby was healthy with no downs. I wouldn't have an amino, there is a miscarry risk. I would take the blood testing approach before the amniocentesis.