I kindda agree with khakhok on the sentiment expressed.
If your expiring EAD is category C09 (received as a result of pending I-485), you can apply for renewal of EAD on the same category and continue working for additional 6 months with the receipt notice. USCIS will probably issue renewed EAD within that time.
If the USCIS has not sent you a receipt notice in 15 days, it will probably send you the entire application back due to errors leading to rejection.
If the money is tight and can't afford a lawyer's fee, at least get some paralegal help for review of your application. Your errors ultimately will cost you money, later if not now.
Make sure you do the G-1145 also so that you know whether they have accepted your application.
If your employer is hesitating, you can show him/ her the link below: