Morning doc.my vagina burns during urination.what can i buy at the chemist?

Yeast?: If the burning is definitely vaginal or labial -- i.e. not within the urethra (urine passage) -- the most common cause is a vaginal yeast infection. Ask the chemist about an anti-yeast treatment like miconazole, clotrimazole, and many others (active ingredient ending in "azole"). If that doesn't work in a week or so, you'll need to see a doctor or clinic for diagnosis and treatment. Good luck!