Contractions !! How does it exactly feel like ?

Isha86
37+2 weeks today. From last evening I am feeling this sharp 3-4 seconder pain every 4-5 hrs. Is it what we call contractions or something els. Am I very close to labour or is there something to worry about !! Plz suggest guys! Feeling uneasy and restless. Want to wait till 12th at least..my birthday:-(