Can continue work while applied for H4 EAD renewal

I have my current H4 EAD until August 2019, applied for H4 and H4 EAD extension ,
Question is what happenes if H4 EAD renewal has not arrived by August can I continue my work or cannot work, by the way I teach math at US public schools, so schools start from first week of August , what will be my situation for work authorization? Please advise me,

No, you cannot work. You need the card in your hand to continue working. H4 EAD extension is not automatic. Check USCIS website, where they do not list C26 category of H4 EAD