Do you smell Smoke?

So, I am pretty sure that my neighbors smoke pot. Argh, it is so frustrating. How do I know this? Well, about a couple months ago I came home and as soon as I walked into my apartment I could smell smoke. I immediately thought I left my chi on or a candle burning. I dropped my stuff and quickly checked throughout my apartment. Nothing...so I thought maybe the neighbors apartment is burning. I run to my neighbor's door and knock without even thinking. After knocking THREE times, I finally get someone to open the door. (Don't you love my logical thinking?) Our conversation went something like this.

Sarah: Hi, I live next door and I smell something burning. My apartment seems fine but, I was wondering if you could smell it as well.

Neighbor: Ummm....no, I do not think anything is burning. (picture a girl 20-something with the door cracked enough for her head to fit through)

Sarah: Oh, ok. (as I smell it a little stronger) Do you smoke? Because I am wondering if maybe it is coming through my air vents.

Neighbor: Ummm.....umm... cigarettes. Maybe it is the candle? I just blew out a candle.

Sarah: Ok. thanks. bye.

Now, her answer to "Do you smoke?"-- was cigarettes? Did she think I was asking so that I could smoke with her? Why would she assume that I was talking about something else? Anyway, I called my apartment people and told them that my apartment smelled like smoke so they "sent someone" to check it out. They left me a note that said, did not smell smoke. Great, a lot of good that did. I do not know what to do. I do not think it smells bad all the time but it is something that I notice at certain times all of a sudden it smells a little smokey in my kitchen. What do you think I should do? Call the cops? I am SURE that she will know that her weird neighbor who came over in a frantic called the cops. What can the cops do? Maybe I can get a can of extra strength air freshener. Any suggestions?