What Causes Missed Period With Negative UPT And Stomach Cramps?

Hi ive missed my period which was due the 28th november . I tock a test last wednesday but came back negative , but im having all the pms signs still but no period- score breast, cramping and alot if pain in my right side along with really bad hip pain , just want advice what to do , im very ratty , hot and uncomfortable also really dont feel myself if that make sense , like not in my own body , any advice on how can ease it all please?