receipt
My lawyer told me 3-4 weeks to receive the receipt. May be longer or shorter depending on the service center or how organized and prompt the law firm is (to inform you). Anyway, my petition was mailed 6/26 and even though the receipt date and Notice date mentioned on the receipt was 6/27 - it was APPARENTLY received by my lawyer on 7/17. So hang in there. I have seen (from personal experiece) that usually it is definitely the lawyer (if you went through one) receives the notice and a copy may or may not be mailed to the employer. (But if you went through the employer without attorney - I have no comments as I have'nt been through such a situation).
And yes, keep calling/emailing your lawyer every few days for it. YOU HAVE TO BE PRETTY PROACTIVE WITH ALL OF THEM. May be its just sitting in a busy attorneys office for days - who knows!?