Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain using dettol as mouthwash in dilute form is also not recommended and should be avoided especially during pregnancy as it is for external use only and not to be used as a mouthwash.. As far as pain in tooth is concerned it seems that the infection in your tooth has reached the nerves that are present in the centre of the tooth and it is leading to severe pain due to nerve irritation.. This pain cannot subside with simply using antiseptic mouthwash and although you use any of the mouthwashes the pain will not tend to subside. As you are pregnant therefore the dentist is not attempting to remove the tooth to prevent any complications and even root canal treatment is also postponed till you deliver the baby to be on a safer side.. But in case if the pain is severe and intolerable you should consult your dentist as well as your gynaecologist and get evaluated and treatment of your tooth can be planned after consent from your gynaecologist to avoid any complications.. As of now you can take Panadol and also apply clove oil over the tooth or bite over a clove to relieve pain.. Hope this information helps.. Regards.