Hello, I have gone through your query and understood your concern. The estimation of the serum beta-hCG titres is more sensitive and also specific and hence carries more significance in the confirmation/exclusion of pregnancy. The urine pregnancy tests can be erratic if not performed as per the instructions. In the current scenario, you can repeat the blood test after 3-4 days and see if the titres are rising. Though the initial titres are low, a positive pregnancy is indicated when the titres double every 2-3 days. Please remember that tires so low as to go undetected in a blood test cannot give a positive urine test. A trans-vaginal sonogram done a week after the missed period, if you have one, also is useful to clarify the situation. Hope your query has been clarified.