Stealing a baby name...?

I am 26 weeks pregnant with a little boy, and have really fallen in love with a name, but it's a name my best friend has had picked out for about 2 years. She's not planning on having children for at least another 5 years (so she says!) and I've asked her how she would feel if I named my baby the name she chose and she said it was fine, but I could tell she was a little mad. I really don't want to upset her, so should I just choose a different name? It's the first boys name I've liked enough to consider naming my son which is why it's a big deal. What would you do?