I Think Husband is cheating..

I have been with my husband for 7 years only married for 6 mths I’m worried he is cheating on me I’m almost 20 weeks pregnant with his 2nd baby. He works nights and he works about and hr away from home and yesterday he didn’t come home tell 10 or so he said they had to keep him for help that day shift was short but then to come find out he was with one of his buddy’s eating and then about a week ago I found a phone number and a woman’s name in his book he takes cop notes in and it was a woman’s hand wrighting then under it was another number in his hand wrighting idk what to think when I asked he told me I’m not talking to other woman idk.