Hi, for the last 3 months I have been having a 39 day cycle. My last period was 22/11/15. My next expected period was suppose to be 30th December. I am now Currently 1 week 3 days late according to my calculations. I have done multiple hpt test returning a negative result. I have no significant stress or any other changes in regards to food, excersize etc. Is my period just having a moment or is it possible a hpt may not pick up the pregnancy yet if only 1 week+ late. Thank you