Hard tummy, sick, tired, spotted period a month ago, and lower back pain, but test said neg for pregnancy. could i still be pregnant?

Confidence: on the day that you would expect your period by urine pregnancy test can be over 90% predictive of whether or not you are pregnant. However, keep in mind these tests are not perfect. It is always good to get a second opinion from a primary care provider if you continue to have doubts for further testing. In short, yes you still could be.