Is this normal?

So I took a pregnancy test maybe... Five days ago and it came out positive - at least according to the lovely women of Glo who commented. 
My period was due five days ago and is now four days late. Ever since it was due, I have been having horrid cramps in my lower region. 
Sometimes, so intense, I literally have to stop whatever it is that I'm doing or double over in pain. If I'm laying down, I have to lie completely still or lie on my stomach to lessen it just a bit. 
I just want to know if this is a pregnancy symptom or not? It's frightening me seeing as though this is LITERALLY what it's like having my period but there isn't a single drop of blood at allllll.