Can Throat Infection And Delayed Periods Be Related?

hi, my periods late by about 17-18 days; ive taken multiple pregnancy tests and they all have been negative about a day or so ago i started experiencing a dry throat stuffy nose and have been coughing up phlem. and this morning i woke up and was experiencing mild pain on the right side of my abdomin, and when i cough it makes it slightly worse. whats wrong with me?