Might have a leak in the roof

I noticed awhile ago that there was a bit of a stain in our master bedroom on the ceiling. Thought that maybe the painter missed a bit or something. Well noticed last night that the stain had gotten a bit bigger and there was a small portion on the wall also. Think we have a leaky roof or maybe it is from a cold rafter and the insulation is not covering what it should be covering. At any rate. I am meeting our builder out there today at 4pm and hopefully we find the problem and can get it fixed relatively quick. I do not fall in the 1 year house warranty the builder gave us but hopefully he will take care of it on his own. IF not I have a name of a roofer that sounds good.