Just found out

I just got a positive test result and it wasn't planned. Even so, we are both really happy and we can't stop smiling. However I'm a bit concerned because we are supposed to be visiting his brother for Xmas in Australia and we live in he uk. 
I'm sat here with a worried look on my face saying we will have to cancel... He looks like he hadn't thought about it... It's a long arse flight! What are you guys thoughts? Obviously it will depend on how well I am and what my doctor says but have any of you travelled at that stage?