Akasha Ji,
these vibrations are amongst many experiences you will have on your journey...but always remember ji (the hard part) that we are just the 'witness' to the experience....enjoy them, then let them go...for they may never happen again, then the mind will make you feel dissapointed, worried that you're doing something wrong etc...when really you have just moved on and experiencing something else like complete silence and peace.
When i do my 2 hour amrit vela simran/meditation, normally after about half an hour when i'm really deep i start getting waves of vibration...they seem to come through my spine, outwards through cheat region and then to my fingertips...sometimes i get these waves 2-3 times in the 2 hour simran...othertimes they happen every 2-3 minutes for a whole hour. I've learnt slowly not to focus on them...after a while you become so used to them that they do not take your focus from your simran.
the intensity will vary from light vibrations to extremely powerful...be witness to them...then let them go
your love for god/guru and sangat will keep you moving a long your own unique path very nicely.