What you're saying all sounds familiar. Some units have nurses in a line, a particular patten that doesn't change. Some may not have lines, like yours. As you gain seniority you may gain a line. I'd ask your clerk or other nurses if your unit has lines. As for the six or seven shifts per pay period, that's also not uncommon. If you work seven shifts you're not paid for 7*12, you're paid for 7*11.25. That comes to 78.25 per pay period. So to average out your hours and pay some pay periods you'll work 7 shifts and some you'll work 6.