When a single sperm fuses with an egg it is called fertilisation.1 Pregnancy starts several days after fertilisation.
Pregnancy does not begin until the fertilised egg has implanted in the womb, after having travelled through the fallopian tube.2
So if you’ve just had unprotected sex or contraceptive failure, no pregnancy will start until at least the sixth day.
Signs of pregnancy4
- Late period
- Feeling sick (nausea)
- Being sick (vomiting)
- Breast tenderness or soreness
- Needing to pee (urinate) more often
If you think you might be pregnant, take a pregnancy test and/or visit your doctor. If you are pregnant it is too late for emergency contraception because it works to prevent the start of a pregnancy.