It's always a good idea to change your workout routine when things become stagnant. I typically complete reroute my workouts every 6-8 weeks, and often times in shorter intervals than not. Your body simply won't grow at a consistent pace if you don't challenge it, and doing repeat lifts makes your body too comfortable.
Starting today I'll be doing a "100 Rep Challenge" five days a week. My goal is to do between 4 and 6 lifts daily, getting to 100 reps in each. Doesn't matter how many sets you do, just get to 100 before moving on to the next lift.
Here's my day one results. I can hardly type this right now...
Pec Fly @ 30 pounds, 25 reps, 4 sets
Seated Row @ 35 pounds, 25 reps, 4 sets
Flat Bench Dumbbell Press @ 30 pounds, 25 reps, 4 sets
Lat Pulldown @ 30 pounds, 25 reps, 4 sets
DB Curls @ 15 pounds, 25 reps, 4 sets
In between each complete exercise (100 reps) I would do 25 bodyweight squats, totaling 100 by the end of everything. During Seated Row I had independent cables and would pronate my hands during the lift, triggering my biceps. I did the same thing with Lat Pulldown, and also pronated my hands during DB Chest Press (helps trigger the chest).
I'll do this for roughly 6-8 weeks and will post my results! Wish me luck!