Ok ladies I need ideas, so as many know Wednesday is my level 2 ultrasound to see if baby has Trisomy 18, if all comes…

Ok ladies I need ideas, so as many know Wednesday is my level 2 ultrasound to see if baby has Trisomy 18, if all comes out that its ok and we get to find out the sex, how should I tell my 8 year old son?? I wanna tell him right away when we pick him up after the appointment from my aunts, but we will be sitting in a car for a 2 hr drive before that, so I wont have a lot of time, any ideas?? Thanks!