Ovulation tests may be weakly positive when you are pregnant. Ovulation test paper mainly measures the luteinizing hormone in a woman’s body to determine whether or not she is ovulating or to determine the time of ovulation. Some pregnant women may also have a weak positive ovulation test, due to the fact that HCG-a and luteinizing hormone can easily cross-react in the body after pregnancy, resulting in a weak positive ovulation test. There are also women who do not use contraception during ovulation, resulting in the successful combination of sperm and egg to form a fertilized egg, and implanted in the uterine cavity, then after conception, the ovulation test paper may be in a continuous weak positive. It is because the luteinizing hormone will not continue to drop to negative after the fertilized egg has been deposited, so the ovulation test paper will also be weakly positive. But ovulation test paper can not measure pregnancy, want to know whether the pregnancy is recommended to go to the hospital to collect blood to check the HCG value to confirm the diagnosis.