I think that's fair enough, it's only 48 hours and whilst I understand that your ILs are only motivated by love sometimes it's best to show your love by letting people have a bit of space.
DH and I had a massive arguement when I was pregnant with Yasin and I said I didn't want him telling his family I was in labour so I know exactly where you're coming from.
You've still got lots of time to get them used to the idea.