12 week scan is getting closer

Katie • Expecting my rainbow baby Jan 2017 ❤️
And I'm becoming more and more paranoid in case they tell me the baby has no heart beat :( I had a precious MC so I'm super paranoid. Please tell me I am not alone in this? Does anyone know the chances of a missed miscarriage? Or any percentages? I saw the baby and the heart beat at 6w6d but my boobs don't hurt at all now and my sickness isn't as bad. I'm 10w4d now