I usually have a 24-28 day cycle, however am on day 35 now and am still waiting for my period. On day 26 I got heavy cramping and thought my period would start but it hasn’t. Since then I feel more tired than usual, my breasts are a bit tender and swollen, I feel nauseous (no vomiting) and fatigue in combination with light cramping and bloating. I did a pregnancy test yesterday morning, but it was negative. Not sure why I feel so “off” if I’m not pregnant. Could the test be wrong?