Good cover up?

Okay. So I have this feeling that my husband is cheating. He is being extra weird. Like last night, I was sleep. I woke up and it was midnight and he was nowhere to be found in the house. The baby in the bed with me and our daughter in her room knocked out. My husband was in the bed with me. I just happened to wake up because I had to pee. So something says go outside, he is outside, in the car on the phone but when he see me. He says something and gets off wearing his blue tooth head set. I walk to the car and asked "why he outside?" And he like "I can't be outside?" I'm like this late? He says I'm over reacting. So I asked him who he was talking to. He says his cousin. I say okay and let it go. Now it's morning and his cousin call me to ask about the barbecue. I'm like "didn't y'all talk lady night?" He like "huh? Oh yeah. We did." I'm like he totally lying. Then I went to thinking how my husband always leans his phone over on the floor to text and stuff. I asked my husband about that leaving over and he said "he gets service better". Like he can lie. I think he cheating. But he lies very good. I'm getting tired of it. What do I do??!