Markers?

I recently had my 20 week ultrasound and found out I'm having a boy😊😊.while this news is great and we are happy, late we got a phone call at nearly 6:00 pm my Dr. Saying baby has a calcium deposit near the heart and the back of the neck was thicker than normal.

Has anyone had these issues and if so did or does your child have downs syndrome .??? I'm scared and I'm hoping with more testing everything will come out as nothing more than a scare. Markers considered medium and hard