Canestan is fine to use and I'm sure your triple antibiotic cream would be fine too. Sounds like it could be a bit of dermatitis to me though. I had pretty bad dermatitis during my pg and my OB told me it was fine to use my normal steriod cream (which is quite strong). If you're unsuccessful with your Canestan etc you might want to try a mild steriod cream from the pharmacy like Dermaid.