I ovulated on feb 8. Since around feb 22, I have been tired, had increased urination, my breasts are fuller (but no pain), and my abdomen between the pubic area and my navel is swollen (but no weight gain). Since last week, I have also been occasionally nauseous. My period was two days late and was shorter and lighter than normal. While I know these are symptoms of pregnancy, I have used 4 home pregnancy tests (the last one today), and all have been negative. Could these be symptoms of something else, or is it just possible that I am one of those women that these tests don't work on? I am 37, which may have something to do with it.