I really need help on getting bigger chest. One question that I have is: Do you want to do more reps or go heavy when doing chest? I see people doing (10, 8, 8 6), is this mean that they go light on first few sets? But I won't get the pump if I go light. I need help.

My chest day:
Benching:
135lbs (10 reps)
145lbs (7 reps)
150lbs (3 reps)
150lbs (3 reps)
150lbs (2 reps)

I also do incline db. My only problem is that my benching is not getting stronger!!! Help!!!