Ok typical question.. Is it possible to still be pregnant?

Ok so I have a ten month old, and my periods are usually spot on, maybe vary by a couple days. But my period was due on the 8th, and now its pretty much a week late. I took 2 digital clearblue tests, both came back neg. Used one at night and one during day. I took them a couple days ago, and also took cheap dollar tree tests. With my daughter, the results came up instantly, and even before she could be seen on an U.S. My question is, Am i pregnant or did i just skip a period? Anyone have this happen to them? I am having some sick feelings, and extremly tired, but i just put that off to dealing with a teething baby. Anyone have any suggestions?