The worst paychecks will be the first 3 while you're still in training. AA pays a month late, looking back at what you did the previous month. Then gives you an advance. It's weird and complicated..not sure how PSA does it but it was completely different than how Envoy did.
Long story short, paycheck #1 is $3300 gross. #2 is $700, and #3 is half of $3300, so $1700 or something. Then after that you'll be getting normal paychecks. But those first 3 are killers. Plan accordingly.