Bone fragments unearthed yesterday at a Queens plumbing-supply store aren’t human, investigators said, as cops continued searching the site for the remains of a Baruch College student who vanished in 1998.

Kristina Kupka, a 28-year-old undergrad, was five months pregnant with her married professor’s child.

Her lover and chemistry instructor at the time, Darshanad Persaud, was a prime suspect in her disappearance but was never arrested.

Cops had received a tip that Kupka’s body was in the basement of the Jamaica shop, which at the time was an auto-supply store run by Persaud’s cousin.