I'm Carolyne..I Had Unprotected Sex On 10th Of December And

I'm Carolyne..I had unprotected sex on 10th of December and took an emergency pill meant to be taken within 72hrs on the 3rd day,I also had unprotected sex on 25th of december but did not take any emergency pills,two days after I started experiencing itchiness in my vagina and brownish discharge all through,My monthly periods was to start on 6th January but I only had brownish small clots and drops of brownish blood instead,what could be the problem?I'm worried