I was under the impression that you're not to have sex 1 week after retrieval and assuming you're using your own eggs, you wouldn't have enough days between retrieval and transfer.
I also thought that after ER you should take it easy but it does make sense.
I had never heard of even being ALLOWED (I have had 6 transfers)
BUT i was searching the net saturday and found research that says the presence of sperm increased the chances of the transfer taking!
This is so weird. I asked this same question to my RE last week. He said that they also recommend intercourse the night before embryo transfer. It has to do with a beneficial effect of the sperm on the lining of the uterus.
This is my 3rd cycle and I never did before.....well, they were both negative but I was feeling so bloated and nauseated, that I didn't.