I'm not exactly sure what sort of advice you're expecting...? I'll be honest... from the sounds of it, I'm not sure if *right now* is the best time to bring a child into your relationship (actually, to be honest, it sounds like the comepletely worst time to do it, but thats just my opinion and I obviously don't know the full story).

Don't really have a lot else to say except sorting out the realtionship(/s) that are going on right now, perhaps seeing a counsellor together, working out what is happening and where you both want to go. I'm not really sure if you mean you want to parent together or separately, but if you are having this much trouble right now I can promise that the tension will only get thicker as you go down the fertility treatment and pregnancy journey.