Stressed

So it's 5 am and my boyfriend recieves two text messages from a number not saved in his phone. Of course I had to go and text this person back which it became evident I was talking to another female. When I told her who I was she refused to tell me who she was and if I had anything to worry about. Instead, she just told me to ask him myself. Most men will lie when confronted. Why can't you just tell me?! I'm due in 5 days and now have no idea if he is being dishonest with me. He's just sleeping ever do peacefully over here and I have tears streaming down my face. Help help help!