Are you talking about CVS screening? We decided not to do it because they don't have positives, only "Negative" for abnormalities or "Inconclusive". I don't think you can get a false positive. But you may be talking about a different test altogether!
And you're not old at all. I'm 33 and was told they don't consider me at a higher risk until 35. Wishing you a low stress test and outcome.