The great embryo debate

This is a very personal and controversial topic.  This is me sharing my thoughts with you.  I am not looking for any suggestions or advice.  I am sure the answers will come to us in time...
The whole time you are in the process of an IVF cycle all you do is count your eggs.  Every fertility clinic has a different recommendation on how many you want to retrieve.  Every woman wants a million.  More eggs = more chances.  Unfortunately, like everything fertility related, this is not an exact science.  You could have 20 follicles containing eggs and retrieve six.  You could have ten follicles containing eggs and retrieve 15.  Using ultrasound and blood work, the doctors have an estimated idea of what's going on in there, but there is no definite answer until they are out.  Once they are taken from the woman's body (under the influence of narcotics to reduce the pain) they are placed in a dish and either covered in washed sperm or injected with one particular sperm.  This depends on your "issues". And then, like everything fertility related, you wait.  By the next day any eggs that have been fertilized contain a bubble that let's you know that things are a go.  From there, the fertilized eggs become embryos by cell-division.  The ones that don't fertilize are discarded.  Around day 3 of the waiting, the embryos contain approximately 8 cells and are ready to go back in.  A woman my age usually can transfer two embryos back into the uterus.  Any remaining embryos are graded.  If they are doing really well, they can be frozen that day.  If they are struggling a bit, they are grown for another two or three days and will be frozen at that point only if they do well.  So, as you can see, the number of eggs can be whittled away in the process of becoming an embryo of choice.  Frozen embryos remain frozen until which time you determine you want to try again.  When you are in the process of a cycle, you want lots of embryos in case it doesn't work.  You want as many chances of success as possible.  In our second cycle, we retrieved 8 eggs.  Only six of those fertilized.  The two best were transferred back in, two were frozen on day three, and two did not make it to be frozen later.  One of the two transferred back became my blond haired, blue eyed beautiful baby boy.  The other tried really hard to make it, but stopped growing when I was five weeks pregnant and was absorbed by my uterus. 
We are now a wonderfully happy family of four.  We have been trying for so long to have a family and I really just want to be happy.  I fear that I have already achieved more than was possible and that I should thank my lucky stars and stop pushing my luck.  I always thought I would donate my remaining embryos to someone who needed them.  My daughter only became my daughter because of the selflessness of others.  I should try to be as kind with someone else in need.  Right now, in Canada, they are working on an anonymous embryo donor program.  I thought this would be a fantastic option for us.  But now I have Jack.  I see how wonderful he is and wonder what those embryos could become.  There is a very low success rate with frozen embryos so it could all be for nothing, but what it if wasn't?  What if I am meant to be the mother of those children? 
But, what if I'm not?