Can I use my Delta account even though I don't have my card with me?

In your wallet on the delta ap it has your card. If your a member.

Yes, just give tge number to the receptionist to verify.

Have ti have the card.

You need boarding pass plus a card that gives you access (Delta Sky, Amex Platinum, etc.) to enter.

The lady said you must have the card for her to scan.

Yes. When they scan your boarding pass they will see you are a member. Just show them the boarding pass.

There are delta reps at the club that are very helpful and I am sure can help you.