Hi I'm a heart mum, not the same condition, however would be similar operations, my son has faced. Its a scary, overwhelming time for you both. Have you been given the name of the defect they are suspecting?
There are many support groups via Facebook or online. Children's heart federation, children's heart surgery fund, from the top of my head.
My son has had OHS (open heart surgery) 4 times now, and is 10 next month, he also has Digeorge syndrome. We found out at our 20 week scan, and was told he had a 55% chance or having digeorge. My son has TOF with Pulmonary Atresia with MAPCAS.
My son has had three procedures including OHS at GOSH, and are a great team. You will have alot of scans etc to attend during pregnancy, and will probably be a planned birth, (im only talking through experience) however aware many peoples experiences are different.
Hopefully once the referral has been made, you will be seen ASAP, we were seen within three days, however this was 10 years ago, and at LGI.
Until your aware of the full facts, from the detailed scans, try not to Google, as its terrifying, I did, and I had worked myself up so much for that first initial appointment.
Make notes of all questions you both want to ask, and take it with you, and try to write down as much as possible, as you will receive lots of information, you will also be assigned a cardiac liason nurse, who you can contact as much or as little as you please.
Take care, there are many options available for you both to talk through and decide, and only you both can decide what is best for you and your child.