Hi I was wondering if I only had three drinks of a beer would it show up on an EtG ua test three days latter

Three drinks of a beer? What does that mean? Do you mean 3 sips out of one beer or 3 beers out of one case or 3 cups out of a keg?

If it was only 3 sips, you'll probably be OK... otherwise, probably not.

Yes it was three sips less then one beer