Bloated Red Eyed Tree Frog?

[kimmy]

Hi,

I have a red eyed tree frog, around 6 months old, I noticed last night that when he was sitting down, his belly underneath him looked kind of swollen or bloated. I'm not sure if I'm just being over-cautious or if there's something wrong :/

He has a large vivarium, with silk ficus, moist paper towels, water dish and a branch ...
Kept between 17 and 21 degrees and humidity is kept between 70 and 80 % ...
I clean him out everyday by replacing the paper towels and the water ...
I mist a few times a day to keep humidity up and to keep the paper towels moist ...
I feed him everyday and dust with calcium/D3 supplements every second day ..
He usually eats between 3-4 1st black crickets everyday ...
I only threw one cricket into his tank tonight to see if he'd eat it, he hasn't spotted it yet but hopefully he will ...

Any advice would be appreciated as I'm very concerned for my baby ....

Thank in advance