Let me start off by saying I have very regular 28 day cycles, I have not been even a day late for as long as I can remember. Yesterday I was expecting my period and much to my surprise it did not come, not even the usual pms cramps I get hours before I start. Since this has never happened to me I decided to go get a hpt from walgreens. This was an off-brand cheapie so im not sure just how reliable it was. I brought it home took it and it was negative. Now im really confused, is there still a chance im pregnant or should I believe the test? Any comments or advice would be much appreciated.