Will one dip of chewing tobacco the day before a drug test show up?

I'll guess "yes": I've heard it said that it does - even for a long, long (40 day time). So, even if that's an exaggeration - one day is not likely to be safe. Hopefully it won't cost you too much - if it does, hopefully you've learned a lesson. Best wishes. Good luck.

Possibly: If whoever is completing the testing is including cotinine testing, a metabolite of nicotine(as in a byproduct your body forms after processes nicotine), it's possible you'll test positive even with that limited use.