Why Do I Have Mild Pregnancy Symptoms Like Abdomen Soreness After Abortion Followed By Sex ?

Had an abortion at 5 weeks on Oct 7. Had sex Oct 27. Brown spotting for one day on Nov 5. I have been having many mild pregnancy symptoms, along with cramping off and on and a very strange sensation... kind of like soreness in my abdomen. I'd like to say its my uterus but not sure. Have not had any period besides the one day of spotting since the abortion. I have taken many pregnancy tests wondering if I was pregnant again but all were negative. What is going on with my body!?