Hello,
Your procedure is exactly same as mine except the dates.
I paid the fee on Jan 28, 2015.
I entered the US on Feb 3, 2015. (POE)
Elis system changed the status "Accepted" to "Optimized/In process" on Feb 25, 2015.
Now when I check the status on USCIS with my receipt, it says below,
Case...