The tests are sensitive enough to pick up the trace amounts of opiates in them... But the poppy seeds that are used in cooking/food/etc., aren't opiated poppy seeds. So no worries! You can't become dependent/addicted to these kinds of poppy seeds.:)
It's like hemp comes from a species of marijuana that doesn't have more than trace amounts of cannibinoids.
Asiatic Poppies are the opiated ones. While generally illegal in the US you'll still find them in churches/parks/private properties that planted them before sale became illegal / they're grandfathered in (and almost impossible to get rid of... Many public parks have tried... But weeds are weeds, they're durn good at surviving!). Even Asiatic Poppies, though, the seeds contain very low amounts of opioids / aren't a good source for making opium or other derivatives. The concentration in that plant aren't in the flowers/buds/seeds (unlike marijuana)... But in the sap, the poppy "milk". To make opium/heroin/morphine/codeine/etc. you take a razor blade and make thin slices to let the sap/milk ooze out, and collect that (or more waste fully, boil the whole plant). The seeds are essentially worthless / you'd have to consume almost a kilogram of them to get the same effect as less than a gram of poppy milk. Even in nations which grow poppies for opiate production? Don't bother with the seeds / they get used in cooking or to mark roadside bombs / etc. But poppy milk? Super opioid rich poppy milk? Still has to be refined & go through a couple steps to produce opium, much less the even more refined versions (heroin, morphine, codeine, etc.).
<grin> Poppyseed bagels & muffins are my favorite!
Eta... Now I wanna bagel! :P