clear blue digital -I am confused

Alex
Ok I need advice, may be some one been in that situation before...I'm on day 28 of my cycle (usually period starts by day 26) and only have very very slight yellow/brownish/pinkish discharge and no period. I have been having cramps and mood swings and nausea for the past week or so. Took two clear blue digital pregnancy tests today. Both came up as negative. This is my 2nd pregnancy (have 8 year old boy) and I know how being pregnant feels, also first time around my tests were negative until 5 weeks. So, after reading reviews on clear blue digital tests and finding out they sometimes give false negatives and how people opened them up to find second line I did just that. Pregnant or not? What does everybody think?