I named my baby Alexander. I have kind of regretted it since he was born, (I think he looks like he should be called jake)
I like the name Alexander, but not Alex and it's my cousins name and friend's 4 yo. Since he's been born I also feel it's not a very comforting sounding name when I'm talking to him and saying his name, unlike my other 2 dc's names.
Dp loves the name and it is the only one we could agree on.
I heard myself saying his name a couple of times while we was walking back from the school run, and he was screaming his head off, colic bless him. Anyway I thought I sounded a bit pretentious, and instantly thought knob!
I really don't want to shorten it to Alex, although many people already are! 
I don't want to be 'that' mum (though this may just be in my head) and correct everybody who calls him Alex!
I'm ok with lex, but it doesn't sound comforting. I would end up calling him lexy, which could end up 'sticking' but that's a girls name really! I really think the person can make a name. (I hate dp's name, it's just a fat name, the type of name I could imagine the dad from the royal family being called, but my dp is hot!)
I don't want to call him by a girl's name!
I don't want to explain his name 'his name is Alexander, but we call him lex, except I call him lexy' or 'HIS name is lexy' the latter, could maybe be acceptable? The former is madness.
I would have loved to have called him Andrew, after my uncle, who I never met because he died when he was 19. I couldn't name the baby after my nan as we had a boy, so this was the closest way I could think of doing that!
But, dp's closest friend, who we visit regularly, with his dp and their kids, is called Andy. Which, I MUCH prefer over Andrew. Obviously!
I've clearly spent too much time thinking about this in the last 4 weeks!