1st Perinatologist vist today

So, I went in for my first visit with the Perinatologist today.  They commented more than once how beautiful and perfect baby looked and was measuring...yay!.  It's always amazes me to be able to see my LO in utero, kicking and waving.  My youngest said the baby looked gross...lol..said it looked like a skeleton.  So, I had to explain why.  HB good at 169 bpm.  They did a VERY thorough scan and checked all the organs and parts and took measurements, so it took a awhile.  The Dr. came in and looked awhile also.  He said the name of what I am dealing with is called "Duffy A".  Good news is, since I've had my last baby (10yrs ago), they've come up with better ways of testing.  Instead of the Amniocentesis, they can now look at the blood flow in baby's head, through u/s, to help determine whether baby's red blood cells are being affected negatively.  But, it's still a little too early to do this.  If worst comes to worst and baby needs help they will do an intrauterine blood transfusion.  But, hopefully, it will never get to that point.  My next appt is in 4wks and the next steps are to: 1. Have my DH come and give a blood sample.  The dr. believes the antigen could likely be coming from DH, so they will test him for it.  If one strein shows up that's no biggie, if two streins show up that could be more of a potential problem, so they really need to rule him out.  2. They also will be getting all my medical records from the hospital where I had my last DS, so they can look over every detail of what happened last time and that will provide them with much more info. and direction.  Sooooo,,,,,looks like Jan 16th will the day I find out what I'm having!!  I'll be in my 18th wk.
This is all still pretty confusing and I wish I could explain it better, but I don't fully understand it all myself.  I guess I'll get a better understanding as I go through it.  But, the main thing is baby is doing beautifully and doesn't seem to be phased by any of this.