What has to happen before you can be legitimately worried you have a stalker?

My house mates and I are a little bit scared…..

Last week I was up late working on an assignment, and I heard someone walking around in our back yard (they were wearing thongs). At first I thought it was my house mate, so I wasn’t too worried, but then they stopped just outside my window. I asked who it was, and a man’s voice came back, meowing like a cat “MMMEEEEOOOOOW, MEEEEOOOOOW”....I was kind of freaked out, I froze. And then after a while I heard them run away. My house mate heard everything, and we were both really freaked out for the rest of the night. I didn’t sleep very well.

Yesterday morning my housemate found a bunch of 6 long stem roses in our car port….(I had ran over them when I got up to go to the gym really early when it was still dark)...there was no note, no nothing…just these roses. They must have dropped them off somewhere in between 11pm and 5am.

Both my housemates have boyfriends who didnt leave the flowers, and I am definitely not seeing anyone, or flirting with anyone who would be leaving me flowers.

Should we be worried that something a bit “not right” is going on here? Is this enough to make us worried? Or are we being paranoid?