Im blessed!

This is my first pregnancy, im expecting a baby girl. When I went in to have my 20 week ultrasound at the hospital where they did measurements on her size. Shes healthy and in the 92 percentile. But I got a call a couple days later saying she might have atrail septal defect (ASD). I've been trying to not stress and worry. But it's hard, I want her to be healthy and happy. So I guess im asking if anyone else knows someone who's been through this? And if theres tips on how to stay calm until I know.. Thank you

Update:

I went to have an echo done on her heart, they did tell me that she has AVSD. Her heart rate was at 70. The way the Dr talked to us just made it sound like she was not going to make it. Me and my husband struggled with that news and made it a long night for us. The next morning we went to the other Dr and they did a ultrasound on her to check her measurements. Her upper arms and legs were measuring shorter then normal. Her heart rate was 68. I had some apple juice and it went up to 72. Then we waited for the results and they got a bunch of Dr together and said that this problem will more than likely resolve itself before shes born. That was a good news! But I hadn't done any blood work for this pregnancy, so they suggested I do it before I went home. They sent my results off yesterday to text for down syndrome. They say im at high risk (75%) because of her body measurements, low heart rate and her heart defect. I'm scared, but happy that, my little one will be okay!