Family is going to a water park in a few weeks, I'm pregnant should I go?

my fiances sister is graduating and her parents are taking everyone to a water park in July I will be 15 or 16 weeks pregnant then and i will be off my bed rest at 14 weeks, i'm not on strict bed rest just can't lift anything heavy and just watch out for overdoing it. His sister really wants us to go especially my two year old and i'm not comfortable with him going without me, I just don't want them to spend $40+ on me so i can stand around and hold my son while everyone else goes on the rides he can't, i'm pretty sure the only thing i can do is go in the pool i will have to talk to my dr. about the wave pool. ugh i don't know what to do!