Help I'm 24 weeks pregnant and need a tooth extracted!

I hope someone can give me some advice. I have a chipped took that had a previous old filling. Now that I'm pregnant it is giving me so much trouble. The pain is unbareable and tylenol no longer works. I want to get the tooth extracted, but I'm afraid that when the dentist pulls my tooth it will allow some of the mercury filling to get to my blood stream. I'm extremely worried about my baby's health. but I don't want to pop pain killers everytday! What should I do? Is tooth extraction safe?