Is this considered a stalker im really confused!!! help?

Ok so i have been getting wierd phone calls on my cell phone wierd messages have been left then i keep getting these strange IMs in the middle of the night either at 1 2 3 or 4 in the morning..i change my name but somehow this person always seems to get it...its been goin on for a while now last night i was on my way home and this person gets right behind me and keeps flashin there lights and turning them on Bright !!! then the speed up and try to p me ...and my outside dogs bark near my room at night???i dont no i have never gaveout my picture or anything could this be a internet/real life stalker? i have deleted my myspace and i have changed my screen names numerous amounts of time its really getting me freaked out!!