You need the dentist, now, to decide how to deal with the tooth, either an extraction or a cap or filling, and probably antibiotics. Don't let infection from a tooth continue in your system if that is what is going on, it is dangerous to your whole body not just your mouth, and of course you don't want it in your system when you are pregnant. Get an emergency appointment with any dentist you can, don't wait.
Go see a dentist but for now try gargling with salt water. Your baby isn't hurt inside but if it is an infection in your tooth and it doesn't get fixed it could move into your blood which would be bad.