Since my last day in the Army was a few days ago, will I still get one more paycheck by the first of next month?

Your last pay will be held around 45 days or so till DFAS determines that you don't owe anything

Assuming your ETS was 16 March or later, and you did receive a midmonth for 15 MAR, you will get one more pay check for those duty days, minus any debt. That will be EFT.
If DFAS finds any additional unpaid pay or entitlements due to you in the audit next month, that money will arrive as a check in the mail to the address you provided during out-processing. If the audit finds any outstanding debt after your last paycheck, that will come out of your tax return next year.
https://www.dfas.mil/militaryseparations/FinalPay.html

What did you final out-process with finance tell you?