A few tips for picking out the right bra - Trouble shooting fitting tips
Is the bottom band of your bra digging in so you cannot move your fingers easily beneath it?

This may indicate that the lower band is too narrow for the body tissue or that the band size is too small. Check the chest measurement for appropriate sizing. If the midriff is fleshier, a wider bottom band would be appropriate, particularly if the band currently worn is thin or rope-like.