Late period.

My periods late! But I always have a very very regular peroid. It comes on the predicted date 8/10 times. And 2/10 times it's one day earlier then my predicted date. Well in two days late on my period with a throbbing headache (how fun..) and my nose acting up (oh how I love not breathing!). I took a pregancy test and it came back neg. But my boobs hurt even against my shirt. I have no ideas what's going on with my body!