new bra guidance please!

[wewereherefirst]

I ordered a nursing bra online and received it today, the back rides up and the middle doesnt sit flush to my chest.

I would need to size down in the back, but would I need to up the cup size too?

when you pull the bra against the chest, do the cups fit? If yes, then you need to go up 1 cup size per each back size you go down. If it's too small even now, more cup sizes.

The cups fit when pulled so I'll order up a band and cup to try, thank you!

down a band and up a cup, right?