What does it mean if you take a pregnacy that comes back positive and your on the IUD paragard and expierencing a lite menstral period with cramping?

You're pregnant. Urine pregnancy tests are very accurate. Just because an iud is in place doesn't mean you can't get pregnant. You should see your doctor right away. If it's very early in pregnancy, it's possible the iud can be removed without harming the pregnancy. You also need to make sure the pregnancy is not in the tube; which can be very dangerous.
Be seen. It is possible you have an ectopic/tubal pregnancy, and need to be seen immediately. There is also a small risk of an intrauterine gestation with an iud, in which case the iud needs to be removed. This runs a 25% risk of miscarriage, but keeping it in raises that risk to 50%.