Entertaining a toddler while pregnant

I'm used to doing a lot with my 2-1/2 year old son. But now being pregnant again it's really hard to get moving most days. I just want to lie down because I just don't feel that well. I feel so bad for him because I know he gets bored. Right now we mostly stay home and play with toys or read books, but my desire to get out of the house is just not there. Some days, if I don't have nausea, we go to the gym so he can play there and I try to work out. Anyone else in the same boat? What do you do with your toddler?