You can not
You cano not do FP without notice. You can go earlier than the date mentioned in the notice but there is a risk involve with it. FP is valid for 15 months. If you do it early and your I-845 take more than 15 months after FP, you have to do it again. The problem is TSC does not track it, you have to call them and remind them to send you another notice so you can go and do FP again. Believe me this is a real pain. So its up to you. If you want to take a risk you can go early but can not do it until you get the notice.
