Hi.. Thanks for the query.. As per your complain pus spot on the gums that is also draining is most probably due to dental abscess formation.. It occurs due to deep Infection in tooth that is leading to pus formation below the root tips of the tooth that perforates the bone and accumulates into the soft tissues.. Bad breath is due to infection and infected pus formation.. In case if you do not have tooth decay then it can be probably due to gum abscess formation.. I would suggest you to consult an Oral Physician and get evaluated and a thorough clinical evaluation and investigation like x ray can be done for confirmation of the cause.. If there is tooth abscess then Root Canal Treatment can be done under antibiotic and analgesic cover.. If there is gum Abscess formation then deep scaling and Curettage followed by antibiotics and topical application of gum paint can help.. As of now antibiotics like Augmentin and Metronidazole can be taken by getting prescribed by a Dentist or Physician.. Gargle with flavoured antiseptic mouthwash.. Hope this information helps.. Regards..