A minor chord have a problem

Don't quite understand

I was looking at chords to scale I just picked A minor and notice that I can play the scale Dorian but this has F sharp in and A minor has no sharps or flats and then I notice that I can play E natural Minor over the chord A minor can someone please explain how the scale will fit over the A minor.

Many thanks

i think the basic theory is like this. and a i'm sure someone else could explain it better.

if you playing i the A Dorian scale whos has the notes A B C D E F# G

the A minor chord has notes A E C
these notes are also in the A Dorian Scale

We can also play the D major scale it's notes are D A F#
as you can see again it's note fit into the scale A Dorian

now with an E Major chord that is made up of E B G#
the G# is not in the A Dorian scale so would not fit.

I hope that helps i think you were aproning it backwards

I'm not really sure...but this is what i came up with...A Dorian is in the key of G major...A Natural Minor is in the Key of C major...G is the 5th of C. So in a way, they are kind of related. Im sure there are other connections, but that was the first thing that came to my mind.