Jillian Michaels 30 Day Shred question-to go up a level or just use bigger weights?

[MooncupandPizza]

Ok, I have done 3 days of this and think I need to make it harder for myself.
I have been using 3lb weights but have 5lb ones so could switch to that
or
I could go up to level 2 now
or
I could do both.
What do you think. I have felt it for sure in my legs and bum doing level one but not much in my arms and barely at all in my abs..

WWYD?
I think I might go up a level with my 3lb weights this evening and then add in the 5lb ones if tonight goes ok..or maybe have both to hand so I can start on the 5lb ones and move back to the 3lb ones if it seems too much?

I would (did) stay at level 1 for the ten days but i always lifted as heavy as i could whilst mainatining form for the exercise. I have a collection of weights to hand which I swap through as i do the dvd, with an aim to be pushing for full range and reps.

I would up to the 5lbs for a couple of days, and of you're still not finding it mega challenging then go up a level.

I was quite strong when I started shredding this time (at the beginning of the year) and found 2.5kg (so about 5.5lbs) was perfectly doable for level 1