My dogs drainage tube has fallen out?

My bull mastiff has had an op to remove a lump in his throat area and along with stitches he has had a tube put in to drain the excess fluid. It was due to be taken out this saturday however it has fallen out whilst taking him for a walk, he has shown no signs of it hurting infact im pretty sure he hasnt even noticed... shall i take him to emergency vets or wait till the morning and ring my regular vet? Any advice would be great Thanks