AF came again :(

When you're early twenties and reasonably fit and healthy you would think you'd just become pregnant at the drop of the hat. I just feel like something is wrong with me and I'm a failure. I really thought I was this month I just felt it and now AF has come and I just feel so gutted. I was getting really excited. I started looking at clothes etc. I just feel like I will never get pregnant because good things don't happen to me. Feeling so miserable right now.