Started having lower abdominal cramping for a couple days, period is late 5-6 days, took one pregnancy test today but it came out negative?

Blood preg test. Is what you need, and some other blood work, and an exam and pelvic ultrasound, if there is nothing abnormal going on after the results of those tests are known, sometimes you can take Progesterone for a few days to induce a period, u should see your obgyn md.