Positive tests after chemical

How long did you keep getting positive tests after chemical? I went to the doctor today because I started having cramping and bleeding last night. They did a beta test that came back only 16 so more than likely it’s going down. I go back Monday to check levels again. I still had one digital test left so I just took one tonight out of curiosity, and still got “pregnant.” I’m just wondering how long you ladies got positives.