hmm...one friend of mine ran into same situation, but USCIS informed her that she was missing some doc, she sent that and got the OPT card...hope its  not the same situation with u..

FYI..

I sent mine on September..10th....through USPS.. they gave me tracking number but it never showed up online...After a week my traking number worked and it said, it was delivered to houston. But that was the place I sent mine.

Went to international advisor, and guess what they got my mail, that was after 2 weeks, I asked why it got returned from USCIS, and according to my international advisor, it never reached USCIS, coz...that USPS a**h*** didnt  stamp my letter, so it got returned. They said they mailed it again, now i dont have any tracking number, dont know weather they sent it or not, no check cashed..then direclty on december 1st I saw the balance reducing from my a/c, checked the back of my check, it had tracking number , went online and checked, said case received and pending. After 2 days, case was approved, after a week got call from international advisor to pick up EAD.

Damn i wrote the whole story here, so dont worry..atleast u have receipt number, either u;ll be asked to provide some  docs or u'll get ur EAD.