Dream of chased, person, caught

In the past 3 - 4 weeks I have been having a recurrent dream that I (or someone) is being chased by another person (male person) (I am female) who intends to attack me. In some of the dreams once the chase starts I remove myself and view the scenario as an onlooker however once the chaser catches up I am no longer the onlooker and return to the victim role. In each dream I wake up before the attack starts however each wakening is getting closer to the actual attack and in my most recent one (ie lastnight) the chaser caught me and pulled out a knife. I have no idea why I have started having this dream!