On keflex have developed a yeast infection down there given meds for that by can't take yet. can i do over the counter cream treatments for now???

No need to wait: Why can't you take the yeast treatment yet? You don't need to finish your cephalexin (Keflex) first. If in doubt, check with the doctor's office where it was prescribed. But if you want to start OTC yeast treatment, that would also be OK. Choose any product with active ingredient ending in "azole" (miconazole, clotrimazole, etc).