Hi Boo - exciting that you are starting! I think it's really nice that your DH can talk to his brother. Sadly DH's brother is king of dumb comments, so we keep them (and everyone else!) out of it all.
I take my Synarel exactly 12hrs apart, but honestly I only do that because of the advice of BB ladies. The nurse wasn't too worried about when i did it. Thankfully i don't pick up the next drugs until after the u/sound and then the trigger i get after the other u/sound. The trigger comes pre-mixed for me too and the needle gave DH a fright! He looked at me as if to say - rather you than me!
BW - good to hear that your embies are going so strong. That must be so heartening.