Cos I bloody am
The only reason she knows is that DD1 overheard a conversation between DP and I, so we agreed to tell DDs and DSD on a 'special secret' basis. This is what we have in our family for things which must ABSOLUTELY not be discussed with anyone (birthday presents/surprises etc).
We felt that we both had to tell our ex partners as a matter of politeness.
I have since found out that DPs ex has been gobbing off to all her friends and family (presumably in a sneery way) that I am pg.
WE haven't told anyone other than our parents and siblings.
Aaaargh