last march 14-16, i had an unusual period that it lasts for three days, this is my first time ever. apparently, i had unprotected sex days before and during my period. My bleeding stopped then i had a week spotting (brown-pinkinsh-brown) then i had unprotected sex on march 23. Then the night of march 27, i had a red light spotting (bright pink-brown) that lasted march 30. All these cramps was associated with a light cramps and episode of frequent urinating, lightheaded, dizzy, nausea. Then last April 5, friday night i had a light spotting again that lasted till March 10, then on the 11th i had a normal like period but it was dark red and has a tiny dots of blood, with cramps also but tolerable then on the 12th light bleeding that it didn't filled the whole sanitary napkin until i got off from work.Then on the 13th there was barely nothing on my napkin but still experiencing light cramps around my pelvic and lower abdomen. this is my very first time that i had this kind of short menstruation..what could this be?