h1b start date, offer date, filing date, 6 months, their relations

The uscis website says: “You may file an H-1B petition no more than 6 months in advance of the requested start date”;
For me, I filed my h1b on 4.5, got receipt 4.9 and still in initial review up to now.
However, the start date on my offer is 12.10. I am worried, because it seems that the earliest date when I am allowed to file an h1b is 6.10, which is 6 months before 12.10. I am not in US. When should I enter the US?
Can anyone tells me whether my case would be OK or not?
Thanks very much! Any comments would be appreciated very much!

You case is alright.

The legal work start date for FY2013 H1B quota is 1st October 2012 and thus the earliest date one can file H1B petition is 2nd April 2012. No one is supposed to put the start date before 1st October. I don't think there is any issue in putting the requested start date later than 1st October.

Once your H1B is approved and got your VISA stamped, you can enter US 10 days prior to your work start date (as noted in your I-797 approval notice).