Help Please Is This A Problem

HELP
here is my baby day 26 my main stem at the bottom of my baby is skinnier towards the dirt and then it gets real fat . is this a problem what can i do to fix it. on the good side im getting my 400w hps tonite with mh conversion bulb got it off ebay. it came last nite . i only gotta wait 6 more hours for him to get off work. anyway please HELP.

i wouldnt even worry about it, looks like a nice healthy plant to me. If its not falling over or real wobbly i woulnt sweat it. That HPS will make it look even nicer.