My OPT Extension ends 17th Aug 2018.Applying H1.Have to travel to India on Aug1 and return Aug 14.What are the risks

I might have to go to India on April1st or March 31st 2018 and return before April 15th 2018. My travel is unavoidable and I wanted to know :

  1. The risks involved

  2. What measures to be taken

  3. is there chances of COS before April 15th if i DO NOT do Premium processing?