My husband and I are trying to conceive. My period is one week late, but all of the hpts I have taken are negative. I have used first morning urine, and tried different tests. What could be going on here? Is it likely to have false negatives? I plan to go to the doctor if my period does not come at all this month. I have always had a 28 day cycle and can never recall being late. I am not under any stress right now. Any suggestions would be appreciated. Thanks.