Creepy X2

So this morning I woke up at 6:30 to the sound of what i thought was someone knocking on my door again. This time when I said hello it didn't stop it just kept going for a little while. At first I was too scared to get out of bed but I did grab my cell phone off my night stand in case I needed it. Once I wasn't as scared I got up and checked out the apartment and again no one was in there. This time instead of a constant bang it sounded like they were trying to make it sound like a horse galloping by. After i saw that no one was in my apartment and re-locked the sliding glass door I went back to bed and the person who lives above me was really loud so I am thinking that it was something that they were doing was making my door vibrate and sound like someone was knocking on it. Don't get me wrong I am still creeped out but not as creeped out as last time.