36+5 with DS3, settled on a name at around 25w.
With his being a third boy we have used a lot of names already and talked ourselves out of a lot of names along the way - our backups for DS2 now feel like awful dreadful names that nobody should inflict on a child 
Consequently our shortlist this time was very very short and although we're both happy with the chosen name, it isn't The Name in the way that DS1's name was easily chosen and indisputably The Name. We also had this problem, though to a lesser extent, with DS2.
Our position therefore is that we have A Name for this unborn child, which we like and which goes with DS1 and DS2's name and our surname and isn't a known serial killer, etc etc.
But... the most usual shortening of the name itself isn't one I particularly like. There's nothing wrong with it, I just don't think I'd use it myself.
DS2 has a similar normal shortening that I don't use, but other people (notably the in-laws) do. It doesn't bother me precisely but AFAIC it isn't really his name. Pre-school don't use it because they have another child with the shortening and it helps to tell them apart!
In both cases it's the equivalent of my calling him Charles but the obvious shortening is Charlie.
Reassure me that this doesn't matter, or warn me that it will BURN ME UP FOREVER and I need to go back to the drawing board. Please?