Oh @blackcat, you sound like you might be an editor. Mistakes like that erk me too, more than they should. As @sueinmn mentions, you can edit your own posts within a 2 hour window.
If that time has passed, you can simply report it with the correction and the moderating team can edit it for you.

To report a post:
1. click the 3 dots in the bottom right of the message.
2. Write the edit you'd like us to make.
3. Submit.

@triciaot, would you like me to insert the "NOT" in your original message?