at a loss...long post

so my husband works out of town almost all the time. I maybe get to see him a couple days a month if I'm lucky. we've had our issues in the past and we've moved on from those(messaging girls on fb and such). things were going really good and seemed like we were in a good place but I checked his phone one night and found deleted messages to a number labeled motel in his call log so I called it and it was a girl, she denied knowing my husband and hung up on me, he denies ever texting her and won't admit to anything. he promises he's never done anything physically with anyone since we've been together and part of me believes that. but I feel like he sends inappropriate messages to girls yet I have no real proof. I love this man with all that I have and he works hard and supports me(23 weeks pg) and my 4 kids. he's amazing to my children and very attentive when he's here. he's never on his phone when I'm around and doesn't try to hide it or anything. am I just being crazy and hormonal? the worry of him cheating is definitely starting to cause issues because that's all I can think about anymore. I'm constantly worrying what he's doing or if he's doing what he says he is. I'm just at a loss and don't know what to do anymore :(