Is it supposed to show 0 on my 1095A from sept. To dec. even if i paid this before grace peiod ends?

Yes and this may be because of the following reasons.

1. No coverage during those months: If you didn't have coverage through the Marketplace during that period, it would show "0" for the months. 
2. Payments or adjustments were made after the reporting period: If you made payments after the grace period but before the end of the year, your insurer may not have processed the payments in time for the form to reflect them. 
3. Other errors: Sometimes, there may be errors in how the insurance provider reports your information to the IRS.

If you made payments but are not reflected in the 1095A, you may wish to contact the insurer so that your payments are reflected in a corrected 1095-A.