Pregnancy Timeline & Negative Test Results: Understanding Conception & Accuracy

Question
My due date was april 5, 2007 i delivered on april 4th i think my last period was around june 27th but im not to sure.  what day did i get pregnent on? also can a pregnency test come out negitive when you are pregent? I took a test at the hospital on july 16th and it was negative but my midwife said i might have got pregnent around the 11th  i am so confused can u please help me  Thank You

Answer
If you got pregnant around the 11th-13th of July, as might be indicated by your LMP and your due date, a test on July 16th would not have detected the pregnancy.  Implantation does not occur until 7-14 days after conception.  It takes several days after implantation for hormone levels to build up in your body.  So a pregnancy test typically cannot detect a pregnancy until a minimum of 10 days after conception, preferably at least 14.  You got a negative result because you tested too soon.