I just started the PBF routine on the 10th of this month. It's pathetic, I'm still on Level 1 of everything except pushups & squats and I can only do 8 Level 1 pullups so far.
My pullup bar is mounted in a doorway I use frequently - would it be a good idea to try some a couple times a day or should I let those sad little muscles rest completely between regular workouts?
I would say try a couple several times during the day. "Grease the Groove," as they say.
I say just relax and stick with the plan. It's been what, 15 days? If you're a complete novice, you're not going to be pounding this stuff out immediately. Don't be ashamed of "paying your dues" early on.
Do you work hard? That's all that matters. You'll get there eventually.