Just a suggestion...
Would you say 'oh amor' in portuguese? If yes, that's fine, I just never heard it. If not, how about 'ix' (as in ix Maria', except I don't know how you write this), or ai, or uf...
Oh dear is a very common expression in English, oh amor seems much less so.
But since goncin always has to edit my portuguese before it is presentable, it is of course very well possible that I'm talking nonsense here...