Hi Cassie,
So sorry for your loss. We also lost our son to CHD when he was 5 months old. Very similar to you, he had several major heart surgeries but then died very unexpectedly.
I am currently 22 weeks pregnant again, and so can tell you about my experience so far. We were also told it wasn't genetic, and that while the risk of another occurrence of CHD goes up slightly when you've had one baby with it, it's only a small increase, from around 1% to around 2%, I think.
We were offered two extra scans on top of the standard NHS ones, with a fetal cardiologist. One was at 16 weeks and the other is this week, at 21 weeks.
I was put under consultant care straight away, I think partly because of the CHD history, but also because I've had two caesareans and am over 40. However, I am not considered high risk, as far as I know. I'd imagine that just your caesarean history would get you consultant care - it did for me in my last pregnancy.
I believe there's no reason you couldn't have a VBAC in your situation, but this is something to ask your consultant. I haven't had my consultant appointment where they discuss birth options yet, but in my last pregnancy, which also followed a caesarean in my first, they were willing to try for a VBAC up until 41 weeks overdue. I ended up with another caesarean.
I know exactly how stressful and worrying being pregnant again is, but remember that your chances of a healthy pregnancy and baby are good.
My advice would be to make sure that everyone you see knows your history. I've been telling midwives, sonographers, doctors, anyone involved, what happened to us. Although communication has generally been very good, it's usually best to make sure people know.
I am also intending to request extra checks at the birth - hopefully they'll agree to an oxygen saturation monitor and a doctor to listen to the heartbeat. Our son was diagnosed at birth, so that's a particularly stressful element for me.
Good luck.