Could I still be pregnant even if hpt was negative?

Pregnancy tests that use urine have an accurate negative rate at about 50-ish percent, so yes you could still be pregnant and HCG isn't being secreted in your urine at high enough levels. Pregnancy tests given at the doctor's office and in clinics are the same ones you can buy over the counter and test the exact same way. A blood test is definitely more accurate as they can detect HCG levels as low as 1. You can insist on a blood test or see your primary care to ask for one. If anything else to make sure you don't have an underlying reason other than pregnancy because of your new symptoms (which could be a more serious condition).