I'm kinda that way about my BFF, but I work with him so I see him at least 5 days a week at work. I like to check in with him during the weekend and he hates the phone, so we use messenger to keep in touch.

Unfortunately, you don't know EVERYTHING that is going on with your friend, so it could be that he is just busy. I tend to be VERY honest with my BFF, so if I'm feeling a little insecure, I let him know that so if there IS anything we need to air out, we can.