I think I am misunderstanding what program you are finishing. Is there a 5/3/1 program other than Jim Wendler's that you were doing? I ask because on Wendler's you would be doing higher rep work. People are generally getting something like 5 reps on the "1" week and 10 or more reps on the "5" week. On Wendler's program it should take a lot of months before you end up doing any true singles, though there are some versions that add some single work after the main 5/3/1 lifting. Have you been doing Wendler's program or something else like working up to a heavy set of 5 one week, a heavy 3 the next and such? Also, what assistance work have you been doing?
Wendler, in the book and elsewhere, indicates that for someone trying to gain mass he recommends doing 5/3/1 with the Boring But Big template (following up the main lift with 5 sets of 10 of that lift at 50-60% of 1rm, and then 5x10 of a complementary exercise), and eating a lot (including a gallon of milk a day). So, if you want to lay off of low reps for a bit just reset the weights for 5/3/1 and do that assistance work. After a few months, change up the assistance as necessary and let the weights build up to lower rep sets.