I was thinking (dangerous, I know), that the weight lifting days are going to be 45 - 60 minutes, but the cardio days are 20 minutes. Would it be OK to do a few laps in the pool after the cardio workout?

I'm a real water baby, and I love to swim. I haven’t swum in a while though, between no pool access and looking like the great white fuzzy whale.

Or, could swimming be done as part of the cardio? Not sure if that would work, but I know I used to be winded and had a good "rush" after 20-30 minutes in the pool doing laps.