5/3/1's an awesome program. I did about 10 cycles of it and I made awesome gains sticking to it very closely! There's no need to add 5 lbs a month. For most of my sessions, I was hitting 8+ on each 5s week for the first few months. Getting to the rep goal shouldn't be terribly easy, but it should not be hard at all for the first few months.
Best of luck!
"First with the head, then with the heart"