Am I in sub 3 shape?

Would love some reassurance from folks here if that would be possible. My race is coming up in a month and here’s my repertoire going in:

• 28:01 for 5 miles last November (official race)
• 1:17:50 for a 1/2 Marathon 16 months ago.
• 21 mile workout long run last week with first 12 at 8:00 pace, last 9 at 6:38/mile
• Peaking at 50 miles per week in this training cycle
• Average of 40 mpw during last 7 weeks.

My mileage is obviously lower than most training for sub 3, which is the most concerning for me at the moment. Otherwise, I’m feeling fit but I know the marathon is a different beast.

Thanks!