Terrified of blighted ovum

Laura • Married 30/8/14, little boy lochlan
I'm 4 weeks 3 days pregnant and all I can think about is getting to my 12 weeks scan and only seeing an empty sac 😔 my mother had one at 12 weeks and I'm seeing lots of ladies having the same. I really hope it's not as common in first pregnancies. I've already had two chemicals before this one.