wack

Hi, new here, lets see how fast I get a response I need to ask something that has troubled me for some time now; Which foot steps forward when punching??? If you punch a right cross for example, which foot goes first? I beleive it's the right one that steps forward when punching with the right arm, but I'm not certain anymore, It seems I have got better balance when I step forward with the opposite foot... have I done it wrong? Help!!