Period is 5 days late! been nauseous for 3 days straight, no period cramps, no sore breast. 2 negative urine tests. what could be going on?

Could be...: It may simply be that you ovulated a little late, and that is causing your period to start late - with the associated symptoms. It could be a cyst on an ovary, they are very common occurrences, less often, but sometimes causing symptoms of cramping, nausea. Could possibly be a sexually transmitted infection if you have had a new exposure.