4 days late!

So I am 4 days late for AF and I usually have signs of severe cramping and whatnot 3-5 before I am due. And I have 0 signs. 3 negative hpts and Im never late unless its 1-2 days. February was a short month so I get glow could be 1-2 days off but that would still make me 2 days late. Is it possible I am pregnant but I dont have enough hcg to show on a test? Ive heard of this happening before I just dont want to waste money going to the doctor when its nothing.