How often will deer keep on the same pattern or trail i finally saw a doe the other night way across the field should i start hunting over in that corner of the field??

Could be one night - could be one month.

It is impossible to say

Depends on pressure, wind, food, weather, other deer, the deers mood, and 100 other things.

There is a good chance though - if not spooked and she has found some food that she may be back.

Only One way to find out for sure