IMHO it's really crunch time. I think you have unenviable decisions to make but make them you must.
Are you, when push comes to shove, prepared to go along with the idea of a 2014+ wedding with TTC coming after this, if it means staying with your DP?
If you are prepared to wait because you want to be with your DP, do it as a conscious decision on your part. But, as part of that agreement to wait, it is implicit that if there were any major issues TTC (and I am not wishing that on you in a million years) that this is not going to cause immediate, unresolvable problems with your, by that point, DH.
If that seems like an acceptable risk then you should make that choice to do things in the timescale your DP wants, agree it properly together and move on. And tbh who knows what the future holds - things may all go smoothly and exactly as wanted.
But if you cannot agree to do that as a conscious decision (rather than being backed into a corner) then you have other decisions to make.
Namely whether to end your relationship soon as you cannot honestly be sure you do want the same fundamental things. .
Or whether to issue an ultimatum. Simply laying your cards on the table and saying this is what I want for us and this is when I want it, and that's because....
Imagine you are old and telling someone your life story, what sounds right to you? I waited to get married until X wanted to and then we had a few problems having children but I loved him so much it was worth it. Or I was with someone for a long time before I realised we didn't want the same things so I had to break up with him but found someone else.
I do think you need to make one of these decisions and soonish. I just wouldn't want you to end up doing what your DP wants under sufferance. You have to decide if that is okay with you and act accordingly. It's your life too.