Was my house marked? I'm trying to understand what this means.

There were these two men going around my neighborhood earlier today. They were knocking on my door and trying to yank on my storm door to get to my main door. They stood there for several minutes knocking and yanking and yanking. I pretended not to be home even though I'm sure they saw me in my living room. I had moved to a corner to watch them. I do not answer my door unless I know you or am expecting you. I saw them continue down the street and they went to my neighbors door. They didn't stand there nearly as long or didn't yank from what I could tell. I see them leave and they go further down the street not stopping at anymore homes.

I come out to my porch and see two quarters sitting on the porch by my door. They were not there until those men came and left. I was wondering if the quarters left behind meant my house was marked for robbery or something else.