Pregnancy tests work by measuring for a hormone called human chorionic gonadotropin (hCG). This is a hormone that is secreted by the placenta as soon as the embryo starts to implant in the uterine lining (usually about 10 days after conception).
You can purchase home pregnancy tests at any drug store. They typically cost $10 - $20. The woman urinates on the test stick and it measures the level of hCG in her urine. The tests are most accurate if a woman waits until her period is 5-7 days late. However, some of the newer tests on the market are more sensitive and are able to detect hCG 3-4 days before the woman’s period is due.
If the test is negative and the woman’s period still hasn’t arrived a week later, it may be a good idea to repeat the test.
Pregnancy tests can also be done at a health clinic, including the Halifax Sexual Health Centre. The health care practitioner may do a urine test, or a blood test. Blood tests can often detect hCG slightly earlier than urine tests and may be done as soon as 6 – 8 days after a risk.