This may sound funny, but there is a problem with the shape of my upper lip. It comes down in a little V shape in the front of my mouth. It’s difficult to make a good embochure because if that, the air leaks out the sides, and it vibrates. A Boehm teacher I had once said I would never be a good flutist! That cooled my enthusiasm for a while. Anyway, one way I have found is to blow though one side of my mouth, leaving the V part of my lip and the other side of my mouth closed. This seems to work OK. I do plan on taking Irish flute lessons soon, perhaps she can help me out with this. Just thought I’d put the problem out for comment. Thanks, John.
I have a similar problem – I have a big scar on one side of my upper lip. I also blow a little bit to one side. If you can get a decent sound from a Boehm flute, you won’t have any trouble. It’s always easier to dirty up the sound a bit than to make it purer. 
You’re definitely not alone. If you do a search, I think you’ll find an earlier topic on this. I have the V shaped lip and a scar from a childhood incident with a fire hydrant cap (a friend swung it into my face). Anyway, make an embouchure, anyway you can. A lot of ITM players have unique shaped embouchures!
Eric
I play slightly off-center too because of my upper lip. As long as you can make a good sound, the position doesn’t matter. I’ve also got a friend who is a great Boehm player who has the “tear-drop” lip and plays off center. She has a great, powerful sound. I believe Jean Pierre-Rampal, a late great French Boehm flutist, also played off-center.
Whatever works, works!
Jeanie
Trad fluter L. Nugent plays off-center.
Isn’t this whole upper lip stuff just a little over the top? I mean, its not like you really need one at all, do you? 
djm
And that’ll be quite enough of YOUR lip, piper boy. 