Default [q] after i network unlocked. It locked back up. Help.

I purchased a used Incredible S and when I purchased an unlock code online I was able to network unlock the phone. 2 days later it failed to read my simcard anymore, did it lock back up? It doesn't give me the option to enter an unlock pin like the first time I unlocked it, so how can I check if the phone is still unlocked? or how can I input my unlock code again if it needs it again? HELP

Also, the sim card still works fine in my old phone so it isnt the sim.