Friendsgiving

My group of friends are having a Friendsgiving next Saturday. I am 4 weeks n 2 days today. I am not a big drinker but when we go out or hang out I do have just a few. Some of them are watching me closely bc they think I’m going to be pregnant soon, it’s funny to see. I need a good excuse on why I’m not drinking that night. The one I thought was that we’re trying and they say it’s best not to drink bc it may happen sooner or the second was I was on a medication where I can’t drink but I’m not sick. Any ideas are welcomed! And I don’t know if it’s safe to have a glass of wine at this point? TIA