Bro, trust me.... if you were a target.... you would not know it until about 5am when they came busting in like Nazi Gestapo, shooting at anything that moved....
Cops go out like that and they know full well that just their being there will cause people who are doing wrong things to act accordingly.... ever find yourself driving and all the sudden a cop is riding right behind you, you tense up and actually pay more attention to him than you do the road? They know people do that and they take advantage of it too...
If I come home and there are cops sitting anywhere in my neighborhood close to my house... I will walk right up to them and ask whats going on. I have the right to know if there is something I need to keep an eye out for and if there is anything I might could help them out with.... LOL Course if they were watching me and my house they would not tell me... but me coming over to them would at least show that I wasnt worried about them....
Can you see the end of your drive from your house? If you can, take and install a small USB web cam in one of the windows and hook it to a computer adn set the software to record on motion detection (if your software wont do this, you can find some by doing a google) and set it to record while you are gone... come home and watch it. you will then have your answer...