I skipped my period now for longer than a week. i did have a knee operation and they did give me pain block. i have a nova t in. can i be pregnant? i did two home tests and both were negative i had spottong and do have cramps but nothing happens?

Tests are accurate: Today's home urine tests are very accurate and not affected by foods, herbs, common illnesses, sexually transmitted diseases, or medications. A correctly done urine test will give a reliable result 3 weeks after sex (3 weeks after when conception might have been) or 1 week after missing a period. If done sooner, a positive result is likely real but a negative result may be due to testing too soon.