So I Had Unprotected Sex Near The End Of My

So i had unprotected sex near the end of my period also counting the fact he pulled out. I also took two test and they both came out negative and i have birth control implant in my arm i got maybe a month before the sex. But for some odd reason im having heavy brown discharged and some light color goop came at the end not really pink but like a milky white. And it kinda hurts at the end when i pee. What is wrong with me am i pregnant