How and when do I approach my husband about possibly cheating?

Recently my husband told me his family member went missing when I was calling him numerous times. My boyfriend got a new phone and left his old iphone in my apartment which I did not know. When going through my counter I saw a phone thinking it was one of my old phones and turned it on. I saw it was his old phone and I didn't think anything of it but come to find out its signed into his icloud. I hate to snoop but I saw something that was a red flag. He had a womans number saved that I did not recognize and in his call log they are always on the phone. This started on the day he told me his uncle was missing. I mean she calls nonstop and he's calling too. I dont know who that woman is and I dont want him to know how I know but it is extremely alarming and is bothering me and I am going to approach him about. The only people that usually call him are his mother and sister. How should I go about doing this? Im at work and I want to leave and get to his apt by the time I go on lunch break and see what is going on? Or should I wait till the morning because he works overnight?

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He is my HUSBAND. We are LEGALLY married. I’m used to calling him my man my my husband whenever and he calls me his wife at times or his girl. It’s completely innocent. It’s how we talk where we’re from. Nothing crazy please I am not cheating
How and when do I approach my husband about possibly cheating?
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