Unexpected Congrats

Last week as I was leaving the office, I ran into someone who's last day it was at the company and we were saying our goodbye's, etc. when she said 'Congratulations, I heard about your news.'  To which I responded, 'ugh, what news?'  That's when she rubbed her belly and said 'Mr. XX (my boss, aka the Director of our group) told me you were expecting.'  I told her that I had miscarried and that it was no big deal.  Of course, she said she was sorry to hear, blah, blah, blah. 

Then I started thinking, why would my boss even tell her?  This person works in HR so I couldn't figure out what kind of conversation he had with her to even bring up this topic? 

I have two managers, one who is the Director and his Deputy Director.  Both of them are very much aware of my situation and are very understanding when it comes to taking time off for my appointments.  I thought I could trust them, but I guess I need to be more careful next time.  I'm really not upset at them or anything, mostly just curious as to why he would even mention it to HR. 

The whole thing just took me by surprised because when we were pregnant, we only told a hand full of people and then had to go back and tell them about the miscarriage.  So when someone unexpectedly  says 'Congratulations' it kind of sets you back.  (Too bad it's not like 'Congratulations on winning the lottery!' Because that would be such an awesome congrats. Wishful thinking, I know.)