Finally found the right time to tell my very anxious DH about our surprise. He took it the way I expected, being very concerned and dramatic for a few hours, but then calmed down and started to tease me and have a giggle. He maybe had a bit of a talk with himself. I'm so grateful actually that it has gone okay in the end.
We had a little laugh about this being a 'Berliner Baby' because we worked out that we must have been on our trip to Germany when we conceived - we were there 2 months in Berlin. So we have our nickname for the tot. I'm sure DH will have a few more wobbles but I feel much better now that he knows, and we will definitely cope just fine. I know he will fall in love with it too, he even said as much himself.
DH has big problems with anxiety, and suffers with some health problems, so I knew this would be a shock to him going from one to two unexpectedly. He is a good man though, my DH, when all is said and done.