Jackie Has Irregular Periods, Therefore, She Did Not Realize She

Jackie has irregular periods, therefore, she did not realize she was already 14 weeks along when she took a home pregnancy test. However, the test was negative. What could explain this?

A) hCG levels peak in the 2nd and 3rd month of pregnancy and then drop off to levels that might not be detected by a home pregnancy test.
B) By the 12th week of pregnancy, estrogen and progesterone have leveled off so differences in them are no longer detected by a home pregnancy test.
C) Home pregnancy tests are only able to detect changes in a woman's body related to pregnancy for the first 6 weeks of pregnancy.
D) She was using her early morning urine for the test which tends to be lower in concentration of pregnancy hormones.