I recently found out I was pregnant by going to the doctors and taking a blood test. They called me the next day and asked me the last day of my menstrual period. I told them May 11, 2009. They then said that I must be 4 weeks. My question is, is there any way I could have gotten pregnant at the begining of April? My boyfriend and I were having some problems, and we both went our seperate ways for a few days, and we both made some mistakes that we regret. He's happy about this baby, and Im not sure if I could possibly have gotten pregnant around April 2nd 2009. Wouldn't my blood test show pretty accurate results? And if so, this baby would have been concieved in May. Im really confused and need some advice.

Thank you.