OATM migration speed depends on various factor including db size, CPU, memory etc...
I believe you should wait for some time and see if it is moving.
Please see below metalink note, it suggests some of the ways to improve speed of OATM migration:-
Oatm Migration Is Running Very Long On Fnd_lobs_ctx Index For More Than 35hrs, How to speed Up This OATM Migration Step? [ID 1362261.1]
FAQ - OATM - Oracle Applications Tablespace Migration [ID 418225.1]