In a phantom pregnancy can spider veins and major blue veins start appearing? also do nipples darken?

Phantom pregnancy: Has no specific medical definition, and so cases can be pretty different. It is not well understood, and there are few enough well documented cases to draw specific conclusions. That said, i suppose veins and nipple darkening are possible. The clinical name is pseudocyesis and you can read some about it here http://www.Webmd.Com/baby/guide/false-pregnancy-pseudocyesis.

Yes: It is sometimes difficult to distinguish a phantom pregnancy from a normal pregnancy and, therefore, signs and symptoms that can occur with normal pregnancies can also occur during a phantom pregnancy including the things that you have described.