I Have A Cold. We Have A New Grandchild (1.5

I have a cold. We have a new grandchild (1.5 weeks old). I obviously have not gone over there since I felt my first symptom. How long am I contagious, and when does the "contagious" begin. I will not allow my daughter or husband to go see the grandchild either, as they may be get my cold? How long do we wait?