Genetic testing?

So there is a 50% chance my baby has down syndrome (found out at 21 weeks during the anatomy scan). We really don't care about that, we will be keeping the baby either way. but the Dr is saying we should do the genetic testing just to be sure because of the baby's heart condition. However, the cardiologist we saw says we don't necessarily need to because they will do testing after baby is born. I'm 23 weeks and at this point our insurance won't cover it. So just wondering is it something we should just bite the bullet and pay for ourselves or wait and let them test after baby is born??? I just want to make a good decision for baby. Anyone have experience with this?