Alcohol tolerance and pregnancy.

Yesterday I had a few sips of my boyfriends beers, and noticed that i became very drunk, very fast for the amount I had consumed. Having a fairly high alcohol tolerance, i thought it was odd. Im in the 2ww, and I remember vomiting from a small amount of alcohol last time I was pregnant.. I thought it was a coincidence but maybe not? Have any of you ladies experienced the same thing?! Thankyou!