TRY LATEX FREE OR NON-LATEX CONDOMS. OR CONDOMS WITHOUT Nonoxidyl 9 Spermicide.
BUT DO NOT STOP USING CONDOMS!
I AM NOT A DOCTOR.
Could be a yeast infection
If it persists for more than a week after not having sex, and not usuing condoms, should see one just to be safe.
AN OUNCE OF PREVENTION IS WORTH A POUND OF CURE!