I have had this happen as well, when I had an ectopic pregnancy. Quite often, your H cg hormones are not high enough in concentration in your urine, but are detectable in the blood. A blood test is the fastest way to determine if conception has occurred. It was funny when I went in to the ER for severe abdominal pain, and this ultrasound tech comes in and says "is this your first time being pregnant??"! HA.. had no idea I was pregnant and had not even missed my period yet, but sure enough, the poor little guy/girl was growing in my tube : (. Unfortunately I had to have a tube removed and the pregnancy terminated :(.. Just goes to show that blood tests can detect pregnancy very early. Good luck, and Congratulations on your pregnancy!!! Blood tests are very, very seldom wrong. Just watch out for those warning signs.
at 8:07 PM on Feb. 16, 2009