Oh boy does this take me back to when I was in my 30's and trying to have a baby!
We did not tell our families either. My late DMIL was an obstetric nurse so our fear was that would interject herself because of her extensive background in that area and neither of us wanted my late DMIL interejecting herself in that aspect of our life. I loved her dearly but there is a line!

We didn't tell my mother because she is a pathological worrier and would have driven me crazy worrying about the meds, the cost, the procedures, the miscarriages etc. We did tell a few select friends because there were times when we needed their assistance when I was on bedrest and stuff and DH had to go to work. They were people who we trusted to keep quiet and they did. On the rare occasion that some social clod asked me about having a baby, I'd wink and say "We're giving it our best effort". That usually stopped the questions. If it didn't, and the questions persisted, my next response would be "I wouldn't dream of having such a personal conversation with you" said in an appalled tone of voice. That always worked. If anyone persists after that, you have my permission to tell them to mind their own damn business and stay out of your bedroom!
As far as other people having babies, I tried to rejoice for them. It was hard, I will not lie to you. But I told myself that just because I was having a problem didn't mean that everyone else in the world should stop having babies. But I did force myself to be happy, to go to baby showers...life had to go on for me, and I would have felt worse had my friends been uncomfortable around me, so I put on a good act a lot of the time.
I wouldn't mention adoption until you are sure that it is something you are going to do. Why get the family rumor mill going? If you're thinking about adopting next year, then tell them next year.
Tina it is a very difficult time, but you will get beyond it one way or the other. DH & I never had children. We also had concerns about adoption, so did not do that either. We are childfree. We have been fortunate to have relatives and friends who have very generously shared their children with us throughout the years, so we have had the benefit of much love from many children, and I hope we have provided the same back to them...I think we have. Being childfree has enabled us to be the helpers in our circle of family and friends...we are usually available, don't have to find a babysitter, can pretty much drop everything at a moment's notice to do something for someone. Since we have had fmaily and friends who have had some pretty significant health and prsonal isames over the years, the fact that DH & I are so available has been invaluable. It took me a long time to accept that God's plan for each of us may not be our plan, and that maybe His plan for us was to be helpers...not a bad way to be.
Best wishes to you...I will pray that your dream comes true.