Follow what is written in the
Wound Care Guide. It is better really to clean it with plain water or a wound wash than soapy water as some soaps do have things in them that may irritate the wound. If it starts to discharge any pus or the area around it becomes really inflamed and reddened it should be looked at but the most important thing right now is to keep anti-bacterial cream on it and adressing changed at least daily and NOT to mess with it because it could be that alone which is causing the symptoms as sometimes a scab can be yellowy and messing with the healing will cause some reddening of the surrounding area.
With an infected wound it would be sore more than just when you apre picking it in most cases and unless it was very deep or the infection is very bad (in which case the whole area area around the cut would be dying away) whould that be the main cause od the cramping. I think that may be separate, maybe the position you are in when you're picking at it. Cramping is muscular pain rather than the sort of pain you get with a 'normal' wound infection though with a very deep seated one or a deep wound down into the muscle it is possible but then it would be local; it would not usually cause widespread cramping over the whole of your stomach, just muscular pain around the site of the cut.