As the other commenters have pointed out, it's one of the plants in the Scilla genus (Kevättähti in Finnish).
Apparently the most common one we have escaping gardens in Southern Finland is Lucile's Glory-of-the-snow, Scilla luciliae (Isokevättähti in Finnish). Other possible options could be Scilla forbesii (Kirjokevättähti), Scilla sardensis (Sinikevättähti) or Scilla bifoliae (Pikkukevättähti).
The plant is native to Eastern Mediterranian and blooms as snow melts in high altitudes. Apparently, it doesn't really escape very far or spread quickly, and as such is not considered a great threat to native plants.
Definitely went with 14 or 15 when I was breastfeeding, because the girls tended to leak. Nobody wants to sleep in sheets that smell like sour milk.