Diane Krish-Veeramany, 30, said she was working at Manford Primary School in Chigwell, England, Thursday when she went into labor in a classroom, the BBC reported Tuesday.
"Everyone was so supportive and just acted on instinct," Krish-Veeramany said. "Luckily, my husband got to the school before I gave birth."
Krish-Veeramany said she gave birth to her son, Jonah, with the help of teaching assistants Dita Gojnovci, Chris Sword and Sam Mustafa.
"One person was on the phone to my husband, one was on the phone to my hospital and the other to an ambulance," she said. "It all just happened really quickly -- within 20 minutes of these phone calls I'd had Jonah."
Krish-Veeramany was taken to Queen's Hospital in Romford and the mother and baby were later allowed to go home.
"We now joke that he was late for his first day at school as he was born after the bell," she said.
"The school have named the room he was born in after him -- it's now called Jonah's Room."