Do I have to tell him ?

I had a one night stand ( at the time I thought it was going somewhere ) with a close friends brother I’ve known him for years we hooked up and now he’s avoiding me suddenly I found out I’m 5 weeks and I have no idea what to do I don’t know how to tell him cause he’s avoiding me and I rather not do it in text and also I’m not sure if I should tell him at all cause I’m terrified of doing this alone again since he seems to want nothing to do with me and I don’t know what I want to do 🤦‍♀️