Yes, you can't be sure if it was an LD if you can't be sure if you was aware of it. Awareness is the only thing you need to have to be lucid.

Anyway, as Barbizzle said, you could try MILD, but also WILD if you want to. I got my first LDs when I tried WILD even though I didn't succeed. It makes you think about lucid dreaming before you fall asleep, which greatly increases the chance of DILD.

Good luck for you!