stressed and need help

Victoria
I'm so confused. My period is a week late, this is the first time this has ever happened. Sometimes I'm like one or two days late, but never a week. I've now taken theee pregnancy test and they are all negative. I'm so confused and stressed. Why won't my period come, or why won't I test positive! What is going on! I know no one can tell me what's going on just looking for similar situations or positive words maybe