For starters, Ancestry marketing makes your ethnicty seem like an astonishing, new, exact science, when the reality is, that you really need to take it with a very large grain of salt. The science is just not that good yet. Less than 1% ethnicity could very well be noise & nothing more. (i.e. no Irish Ancestry at all) Plus "Irish" to AncestryDNA does not necessarily mean the country of Ireland. It tends to be Celtic markers. That could well be from Scotland, Wales or England, etc.

If you test at other DNA companies you may find quite different results. I suggest taking you raw DNA results & downloading to GEDmatch dot com. It is free, will match you to others who have tested at the big three DNA companies, will give you a much needed chromosome browser, and will give you a variety of other admixture calculators to play around with. By running your results through some of those calculators you will begin to see just how non-exact the ethnicity/admixture science still is.