If you think you may be pregnant but the pregnancy test is negative, there may be several reasons, says midwife Nikki Khan.
"Home pregnancy tests measure a specific hormone in the urine called human chorionic gonadotrophin (hCG), which is only present when a woman is pregnant," Nikki explains. "It's produced when the fertilised egg implants in the womb.
"Some pregnancy tests are more sensitive than others to this hormone and claim to be 99% accurate on the first day of your missed period, but some tests do not always detect hCG levels this early in pregnancy. For this reason, most brands suggest repeating the test in a few days.
"Be aware that the timing of the urine sample may also have an effect. It's most accurate to test first thing in the morning, so always try to test yourself then.
"Of course, the test may have shown a negative result because you're not actually pregnant. If you've missed your period and are experiencing pregnancy symptoms, ask your GP for a blood test to check your hormone levels, which should help to clarify the situation."