Need reasons/excuses for not drinking tonight?!

[PhieEl06]

HELP?! 11 weeks PG & going out for New Years tonight, I need an excuse or reason for not drinking, we're going to our local pubs' fancy dress party & haven't told friends & BF's parents yet who are all going to be there, need an excuse for not drinking as we're not ready to tell them yet?! My best friend has suggested saying I'm on antibiotics but what for I'm not a great liar so this is going to be difficult.
Also can't say I've stopped drinking because I drank like an alcoholic loving fish before!! They would guess so easily.

So just to update, no one had any ideas, made sure BF always brought my drinks, carried around the odd glass of wine & then gave to best friend when we went to the loo, danced around like a bit of an idiot (nothing unusual there) & then when I felt like I couldn't do it for much longer got my BF to make our excuses for us & we went home, didn't enjoy it as much as my usual New Years celebrations but it has got me very excited for what this year has in store!
Oh BF's mom did call me boring but I laughed this off, note to self - we must tell her soon!!