How long does it take for oil base polyurethane floors to dry?

We bought a house in august and it took two months to renovate the entire house. The hardwood floors were done at the end when it was already October and cold. It has been two months since we moved in and the smell from the polyurethane is still very strong, and when I press my nail onto the floor it makes an imprint of my nail! I have a 2 year old toddler and I am 3 months pregnant and my husband and I are very concern about the smell affecting us. Does anyone know if this smell is dangerous and if it is normal to take this long to dry completely.