Feeling heavy?

Keopu • 30-something communications professional mom of 1, looking forward to being mom of 2 in September!
I've been having a great second trimester -- more energy, less sickness, all that jazz. This morning I woke up and just felt heavy. My boobs felt heavy (and I'm already getting the dried colostrum) and then when I went to walk to the bus, my belly and baby felt heavy. I'm getting overall pretty low energy this morning today in general, but this heavy feeling is weird. Anyone else ever feel this way? Any tricks for getting through the work day?