I have applied for OPT extension on sep 25th 2017 and waiting for approval. Due to medical emergency i had to come to India this December and do not have the stem opt approval for my reentry to states. Is it safe to travel united states with the i-20 and the stem opt receipt notice since my application is still in pending. or can i postpone my travel until i receive my EAD card. Please suggest me in this case and what is the average time for stem opt approval, as it has been 85 days since i have received receipt.