Hi Madam, the drugs prescribed to you are absolutely safe. you can use them without any hesitation during pregnancy, but use them as minimum as required. Keep a good oral hygeine. and if you wish to get them extracted, 2nd TRIMESTER (4-6 months), are considered best time for such elective treatment. First three months are very crucial for growth and development of foetus, so extraction sort of treatment which puts up lot of stress on to the mother, and sometime even may necessiate Xray examinations of the tooth are not carried out unless and untill absolutely necessary or in emergencies of severe pain and swelling.