Eight embryos should be enough to take over the world, right?

Clinic Update:

• We received a total of 12 eggs; they were divided into two batches of six each.
• The embryologist decided to allow the eggs to fertilize naturally.
  
• Potato #1's batch fertilized 2 embryos; Potato #2's batch fertilized 6 embryos; this leaves us with 8 embryos to grow.
• The surrogate transfer date has bee set for Monday morning. Both moms are coming with us. We get "babies first pictures" of the embryos.
• The remaining embryos will be cryopreserved (frozen).
  

Next major hurdles will be:

• The pregnancy test on 8/12/09 (two weeks from from the egg retrieval).
• The ultrasound on 9/2/09 (three weeks from confirmation of pregnancy). This is when they will confirm the number of embryos that have developed into fetuses and we will be able to listen to the heartbeat.
  

The big question in my mind that currently remains unanswered is: why day five vs day three? I was told that if the embryologists think that the embryos aren't doing too well, they tend to transfer them on day three in order to get them into the uterus ASAP. Based on some research on our end, it seems as though three days used to be considered the typical transfer period just a couple of years ago, but that by waiting until day five, the embryos have a much higher surface area in which they can connect with the uterus. Coincidentally, it appears that most clinics' statistics show higher success rates overall during the past couple of years, since it became more common to go with the five day transfer. But I really wish we could get a better explanation of just how they determine to go with the three day vs five day transfer. Are they focused on just getting two good embryos to transfer, or on getting one from each of our batches? Will my two fertilized embryos be jeopardized if we are waiting for fertilized embryos from my husbands batch to develop and vice versa? I'm hoping that they are in fact focused on the batches as individual batches to be maximized, as opposed to just getting the best of all eight...

More breaking news as soon as we have it!