I know where you are coming from as well...
My husband and I agreed that people would be included in our IVF circle on a "need to know" basis only. I have only told a few friends and co-workers at work who were also dealing with infertility. My family knows nothing, even now.
My DH, on the other hand (who works in the same hospital as me) told ANYONE WHO WOULD LISTEN THE ENTIRE DETAILS!!!
These people told two friends, who told two friends, to the point now that I have people who I barely said "hi!" to in the elevator asking me details about my experience and my privates!! My husband's entire family knows all about it, including people who my husband doesn't even like!
I agree that it isn't so much feeling ashamed about IVF, but just the simple fact that 1.) I'm not 100% sure this pregnancy will last, as I'm still in the first trimester and feeling very insecure about being pregnant at all, and 2.) I simply wasn't ready to announce my pregnancy to the world, let alone having to explain all the hardships of infertility and IVF to a lot of people who don't understand. I don't feel ashamed, but I do feel exposed in a way I wasn't ready for.
When people do ask, though, I try to be polite and educate them as best I can, but sometimes I agree that it is hard.
Me - 37, DH - 46
1 m/c at 26, 1 ectopic at 27
BFP with 1st IVF! 1st beta 60.85, 2nd beta 975!! Its a boy!
3rd trimester starts February 14th.