I haven't … it
I didn't really think about it.
Je n'y ai pas beaucoup réfléchi.
I haven’t thought much about it.
Je n'y ai pas réfléchi à deux fois.
I didn't think twice about it.
I didn't think about it.
Tu crois que je n'y ai pas pensé ?
You think I didn't think of that?
I didn't take part in it.