If you believe you have secured the location, it's fair to assume there won't be an ambush there when you come back some time later.
If there is, it means you did something seriously wrong suppressing the first ambush and securing your rear (assuming you didn't do what the Americans did in Vietnam which was to secure a site, then draw back from that site for no reason, leaving it to the enemy, and then attack it again some time later, surprised there were once again enemies there).
As to being ambushed in the same location multiple times, usually it happens because the ambush was a success and no word of it happening gets back to the commanders of the forces that were ambushed, leading to a situation where a second patrol can be ambushed at the same spot. An alert patrol, knowing an ambush likely took place, will be looking out for places ambushes are likely of course and possibly detect the existence of one (or at least be prepared for one when it happens because they know as well as you do that a place would make a nice one to set up an ambush).
To generalise: what makes it possible to be ambushed in the same location twice is a breakdown of command and control, possibly combined with lack of skill of the forces involved.