just now 有三种含义：
1、at this moment 此时、此刻、眼下
Come and see me later, I'm busy just now! 过些时候再来，我这会儿正忙着呢！
2、during this present period 目前；现阶段
Business is good just mow. 目前生意很红火。
3、onlu a short time ago 刚才；刚刚；一会儿前
I saw her just now. 我刚刚见到过她。
注：just一般不用于否定形式！