Awww sorry you've been arguing mate.
We used to separate the sex out a bit! we'd have what we called "baby sex" and that would be the boring "right, see these 3 days on the calendar? well we've GOT to do it whether we want to or not" sex! Then before and after that we'd have what we called "us sex" (!!) and we'd get really naughty then!! I remember many a time us saying "ooohh lets get a quickie in tonight before the boring baby sex starts" or "yay, last night of baby sex tonight and then tomorrow i'm going to do X to you"!!
I guess this was just our way of dealing with it and trying to stop the TTC taking completely over our sexlife. Seemed better for us that rather than pretend we're not bd-ing for sake of ttc (when we both knew we were) just admit we were and then make bd-ing the rest of the cycle more fun and just for us!