I have a slightly different take on this because my husband was the one with end stage renal failure who needed a kidney, and this was a well-known fact by all our friends and family by the time I found out I could donate to him via paired exchange.
So, I started "journaling" about the testing process via a series of group emails as a way to get my thoughts on "paper," make sure I remembered all the details, and share our journey with those in our lives who were interested. I didn't worry about collecting accolades because they were easy for me to brush off; of course I would donate to my husband, nothing heroic about that. And truly, we found that people were interested (or they could skim or delete the emails, that was fine, too).
I enlisted my step-dad to send out an email message to my list once Joe and I were out of surgery. He went further than that and sent out updates during and after surgery and when we were released from the hospital. Lots of people mentioned that they really liked getting those messages. Plus, it gave my stepdad something do do. And then a week later when Joe had to go back into the hospital for 9 days, my stepdad started sending updates again. I really appreciated not having to worry about keeping people informed.
I found out later that my close friend at work (who was on my email list) forwarded my stepdad's messages to the entire office. It was fine, but getting all the congrats and "your amazing" comments from people I work with was rather embarrassing. But again, I could deflect a lot of it and keep the focus on my husband.
By the way, I also posted pictures of my kidney on facebook. But I am only facebook friends with actual friends and family, so I have no problem sharing my insides there.
Ok, lots of thoughts up there, but bottom line, I think people are interested and it's nice to share important things in your life with people who care about you. So, please consider telling others (and don't worry about the how or the why). I think you'll be glad you did.