Need quick advice right now...

Hi ladies! Just about to head to an all you can drink dinner with a rowdy group of grad school friends. I had committed months ago to go for a friend's bday. We half heartedly tried this month (end od sept and last week) so I don't think I'm pregnant but i could never forgive myself if I am and wasn't careful.

These people will inevitably ask-- why aren't you drinking much? They can be nosy about things like this but i don't want to share yet.

Any ideas what I can say??

Also if I have a couple glasses of wine is that really bad?