Pregnancy can be detected by test strips at 1 month. General intercourse after the earliest 14 days or more, if successfully conceived, can be initially detected through the test paper. Test paper test generally need to test with morning urine, if the usual test, do not drink too much water before the test, so as not to dilute the urine, the results of the test out of the probability of error is very large. Observation time within 5-10 minutes, if the test paper is placed too long, sometimes the test is a positive indicator, there may be some false positives. The test paper test has a certain probability of error, if the test comes out positive, if necessary, you can through the blood HCG test, if the blood HCG test is also positive, can be diagnosed as pregnancy.