Adjustable Prosthetic Bellies?

My mom wants me to feel what it's like to be pregnant, and I want to too. My mom had me when she was 16 (my age) and she doesn't want that for me, so she wants to show me what it's like. I also what to see how pregnant teens feel. I know I can't feel everything but i want to know how people look at you, treat you, who my real friends are, and so one. So basically I'm faking a pregnancy. it has to look realistic though, so thats the thing. I am looking for a prosthetic belly that isn't the empathy belly. That looks to fake, also I need it to adjust to my pregnancy. So i look like I'm growing. Does anyone know where I can get one for cheap? like maybe about 50 bucks. Or if anyone knows one that simulates kicking that would be cool too. :) thanks