You can add an extra note to the minor pentatonic scale and it becomes the blues scale;

You are probably aware that A minor pentatonic is: A..C D..E..G - the extra note is D# and is known as the blues note - however it needs to be played selectively.
IE: it will work well, before or between a minor pentatonic note/s - but if you play it on it's own it will sound.......................................Wrong

This six note scale is known as: A minor blues scale.