PH test paper to measure the acidity and alkalinity to prepare for pregnancy is inaccurate. PH test paper is mainly used to detect the acidity and alkalinity, can detect the acidity and alkalinity of urine, but can not be measured to determine whether to prepare for pregnancy or pregnancy, because the acidity and alkalinity of urine may be affected by a variety of factors, and can not be used as a criterion for preparing for pregnancy or pregnancy. There is no direct correlation between changes in the PH level of a woman’s body and pregnancy, and the PH test is not very specific. The most important reference for a woman to know if she is pregnant is the human chorionic gonadotropin (HCG) in her body. To detect pregnancy, you can use early pregnancy test paper or pregnancy test stick, you can also go to the hospital for HCG blood test to more accurately determine whether you are pregnant or not. If you have any other questions, it is recommended to consult a professional doctor for guidance.