Patient :Date of last menstrual cycle is 10/16. I took a urine test when I skipped my period. It was negative. 3 weeks later took a blood test. It was negative. Still no period. Today got a urine test and it was positive. Whats going on? When was the conception date?
An unprotected intercourse results in pregnancy only when a woman is in her so called "Fertile Period". The fertile period of a woman is determined by analyzing her menstrual cycle with an ovulation calculator or fertility chart. Normally, the menstrual cycle is a 28 day cycle. During the 14th day after a period, the ovum is released. This process is called ovulation and the days 12 to 16 days after a period are said to be a woman’s most fertile period.
A pregnancy test attempts to determine whether a woman is pregnant. Markers that indicate pregnancy are found in urine and blood, and pregnancy tests require sampling one of these substances. Most chemical tests for pregnancy look for the presence of the beta subunit of hCG, or human chorionic gonadotropin, in the blood or urine. hCG can be detected in urine or blood after implantation, which occurs six to twelve days after fertilization.
Ovulation may not occur at a predictable time in the menstrual cycle, however. A number of factors may cause an unexpectedly early or late ovulation, even for women with a history of regular menstrual cycles. Sometimes more than one tests may be necessary especially in those with irregular cycles, as the days of ovulation, and hence fertilisation may not be predictable in some.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.