Newly paved driveway has long cracks : ( !

We had the ~ 20X20 sqft driveway poured in early Jan (north cali area). The concrete pour is about 4 inch deep with pattern stamped, cut was about 1 inch deep. Last week we found a thin but very long crack right in front of the doorstep. The crack doesn't appear along the cut lines but cut through the main floor. We didn't put any heavy weight stuff on this area or accidentally damaged ourselves so we are pretty sure it's probably how the concrete was poured or how the foundation was set up. Even though our contractor never promised the concrete won't crack but it's just 3 month since the project was completed and it already started cracking? We are pretty upset with this and are worried the crack will increase over time. It rained a little this morning, my heart sank when I saw the water made the crack looks really obvious now even with the stamped patterns! Does this look like a poorly done project to you? What can we do to reduce the damages to the minimum before it starts to get even worse?

I've attached some pictures, hope you will be able to see them.

 

Am I seeing correctly that the crack crosses a joint?

 

Concrete cracks... you cant always correctly predict where. But anytime you have an unusual shape that is not a rectangle with a width ratio no more than 1:1.5, you can expect it to crack. I expect that triangle cracked roughly down the middle, into two pieces roughly equal in size, which is really kind of predictable for a triangle of that size. But I bet you wouldnt have wanted him to make a diagonal control joint either, so....

Best you can do is caulk all those cracks and joints.

Im sure it could have been cut differently, but without seeing the whole driveway its hard to say... or make any judgements about how it was done. Also hindsight is 20:20.