I am 8mnths pregnant and im getting a yeast infection. Do I absolutely need to see my dr and have him check me or can I buy something at the store?

Can try OTC Monistat. It is worth it to try an otc med. However if not without sxs in a few days an appointment would be indicated.
Something at store. Ask your pharmacist what topical agents are available and in your price range. There are numerous agents which are very effective and you should not need to see a doctor unless these do not work.