Hey there KnittingTigers!
I actually talked to MY sperm bank, too (California Crybank). They said that the 72 hours is the max that frozen sperm can live, not that it always does. It will live longer in fertile mucus, of course! :)
As far as research goes... Not really sure! I am going to ask them!
Also, on another note: I am experiencing lots of little cramps and tons of bloating- I am 5DPO. Is this normal? I have SO long to wait to find out, it feels like,...