What Causes Light Menstrual Flow With White Discharge From Breast?

Ok so i had unprtected sex well ive been having it for months now no pills but he hadnt ejeculated inside me until last july 28 or 29 my period was july 12 after he did that a few days later i started feeling these cramp like symtoms which i never felt before i do have an 8 year old i dont recall feeling those... I took a HPT the following monday negative im assuming too soon right? Then on Sunday the 7 or Mon the 8 i started my period which has not been normal at all no cramps im a heavy cramper and no blood clots at all which i do have normally on top of that it was shorter and way lighter than usual ive had my period since i was 9 so i know my body well and its always been...i work at a clinic so on the 8 i took a urine test there which was negative also...yesterday i squeezed my right breast and white kind of clearish stuff came out which has never happened since i had my child 8 years ago please what do u suggest???? I need help!!!!