Hi, Thanks for posting the query, Cold sores occur due to trauma physical or chemical, i would suggest you to plan for some other methods of contraception by discussing with your OBGYN. Apply hexigel oral ointment topically over the affected area, take lukewarm saline and antiseptic mouthwash rinses. Take multivitamin suplements , antioxidants, take plenty of fluids which are rich in vitamin C like lemons, oranges. Maintain a very good oral hygiene. Hope you find this as helpful, Take care!