I Am 24 Weeks Pregnant And My Husband And I

I am 24 weeks pregnant and my husband and I have been using a kerosene heater in our first floor because it has been so cold this winter and our electric heating bills have been so high. Our first floor is completely open floor plan(no closed off rooms) but I'm afraid this almost every day exposure might be harming my baby and I. I don't feel ill, but I don't want the baby to have any birth defects from this. Also, I feel like lately....it seems like I can almost "taste" the smell of the kerosene at times even when I'm not in the house. Should we stop using the kerosene heater all together? We haven't been cracking a window because that kind of defeats the purpose of keeping it warm.