Can you have a negative hpt at 9 weeks and still be pregnant? is it true that some women don't get a positive hpt until their second trimester?thanks

No, and not true.: A pregnant woman cannot have a true negative test after 5 weeks of pregnancy. Women who don't do a home pregnancy test until in their second trimesters will not get a positive result until their second trimesters... but only women who cannot tell that they are pregnant until their second trimesters fall into that category. The rest of the women will test in their first trimesters and be positive.

Not likely: Home pregnancy tests are very accurate and a woman's body is very consistent about producing Beta HCG when pregnant. Unless the test is defective, its unlikely that a home pregnancy test would be negative at 9 weeks. Its more likely that your dates are wrong or that you are no longer pregnant. If there is any question, you should get a blood pregnancy test. Best wishes!