 [ Symptoms ] my 12 year old son has pain on his front thigh we visited many doctors no diagnosis [ Disease ] most home pregnancy tests are pretty reliable when used exactly as directed about a week after your missed period so for example if your period was supposed to start 125 then you can start testing around 127 home pregnancy tests detect a hormone called human chorionic gonadotropin hcg in the urine because the sensitivity of each brand of home pregnancy test varies you will probably get the most accurate result if you take the test first thing in the morning when your urine is most concentrated be sure to read the instructions very carefully and time the test exactly as indicated this will help provide the most accurate result if you get a negative result but do not start your period i would suggest you test again the body continues to produce hcg throughout the first few weeks of pregnancy so a negative test could simply indicate your levels were too low to detect the first time good luck