Hello, Thanks for letting us know your health concern. A single line on a home pregnancy test can be due to a false test, defective test kit, improper way of performing the test as the sample of urine should be a fresh early morning collection etc. Please wait until you get the result of the blood test and plan further management accordingly. There is no need to stress as your result will be available soon enough. A trans-vaginal sonogram performed a week after the missed period clarifies the situation further. Hope this helps.