If it were me, yes, I would tell my OB my plans. Of course, I told my midwives and then they decided they could no longer see me...
I don't judge people who pull the "oops", though. I just prefer honesty. It was good for me in the end... it encouraged me to be much more self sufficient and far less reliant on medical care from others. And in the end, it all worked out. I actually did even find an OB who was willing to see me (when the midwives would not!), but just never went in to him since I was already almost done with my pregnancy, anyway.
I do agree with not telling your family.
I would definitely be prepared for the OB to make bigger deals of things. Even a well meaning OB who seems supportive of you... their field of training just handles birth from such a completely different angle, your ideas would be not matching at all with what they feel is best. They will undoubtedly be looking for any potential problems they can find (it's kind of just what they do). In that case, you'd either need to put your foot down wherever you disagree, or stop receiving their care. My concern with that, however, is that if you get the wrong OB who gets very passionate about your situation, they may interfere somehow. Being respected and a doctor and someone who has all your sensitive information and medical files on hand, my concern is this leaves you particular vulnerable to whatever.
And, I can't forget about the Florida mom sentenced to bed rest when she told her doc she wanted a second opinion. (She went on to miscarry, anyway).
So..... hmm, there is really a lot to think about.
Follow Mothering