Each of the five stages of grief are not necessarily experienced in order. You may experience both the denial and anger stages long after you've reached the acceptance stage, or you may skip over certain stages altogether.
For some people, grief can come in waves or feel like an emotional rollercoaster. For others, grief can move through some stages, but not others. Don’t think that you should be feeling a certain way at a certain time, because everyone’s grief is individual to them.