Gaming EV training concerns

[Ziggy Zigzagoon]

I had been EV training my in Attack and Special Attack, yet I noticed two different scenarios when leveling up.
I trained for Attack in Route 101 against Poochyenna. Since my "client Pokemon" was at around Lv. 40, I maxed out the Attack EV without leveling up. When I did, my Pokemon got +7 Attack stats.
I trained for Special Attack at Route 113 against Spinda and Slugma. I ended up leveling up more frequently against the higher-leveled Pokemon. Under this situation, I ended up noticing that I have been getting +6 Attack stats every time I leveled up.
This concerned me; did I miss out on giving my Pokemon Attack points because I did not level up with sufficient frequency when I trained Attack? (In other words, could I have given my Pokemon a total of, say, +30 instead of just +7?)

 

[s4mid4re]

The rate that you level up doesn't matter, as long as you are certain that you gave it 252 EV for attack. The final stat should be equal, even if you level up slowly.