Creating a drivecrypt partition on unpartitioned space?

Hi all
I wanted to encrypt one whole non-system HDD. That HDD had one partition on it and it was set as primary partition on it. In Windows disk managed I have deleted that partition so the whole disk became unpartitioned
In Drivecrpyt 5.4 I've selected unpartitioned disk and choose "format partition as drivecrypt" - so I haven't created partition prior to that formating
After formating partition as drivecrypt, the disk could be read only by mounting and if i dismount it, it wouldn't show in My computer. so i mounted it and filled it with data. Now I'm concerned: when the disk is unmounted, in DC 5.4 it says "offline partition; disk 1, partition 0; unpartitioned disk"

so my question is - is it safe for data integrity to use unpartitioned disk in dsk kind of way? Should I have partitioned it first and then formatted it as drivecrypt? Is there any risk for my data?

I have windows 7 x64