No. Until your return moves into accepted status, you won't be able to amend. In fact, you won't be able to do anything with your return.
But here's what you can do in the meantime:
- First, find out if you even need to amend.
- Keep checking your e-file status or watch your email inbox for a status update.
- Once your return is accepted or Form 1040X is finalized (whichever comes later), you can amend. (If your return gets rejected, make the necessary changes before re-sending or filing.)