My boss told everyone at work..

I was waiting for my 12 week appointment and scan to make sure all was on track (it is thankfully) as we had a missed miscarriage back in December. I popped into work to drop a few things off and everyone hounds me with congratulations. I was confused as I had only told my manager due to severe morning sickness. Then a colleague had said who told her etc.. At this point I hadn't had my 12 week check up and was so upset and angry as it's not anyone else's business to share. There is no reason at work for anyone to know for manual handling/safety reasons so I just feel very put out.
I also asked for complete discretion! 
Correct if I'm wrong but I'm just annoyed.
And breath.