HOw exciting is that??? COngrats...I am trying to rack my brain and nothing is coming up. I don't know you could not tell him right away. I know me and my husband took the test together...well we were together when I took the test...
Maybe you can get him an extra gift on fathers day...like a plant...so it grows just like the baby will and say it is from the new little one...growing for him...something like that....
You know I googled it for you and this is something I found...