Hello. My period date was 19 feb but got on 23 feb four day delay but flow was less compare to before periods. Total 3 pad used and also taken morning after pill this 7 feb and is was periods or one can be pregnant even with this. On 20 feb I checked was negative in urine pregnancy test.
After taking the high hormonal emergency pill one gets withdrawal bleeding 5 to 10 days later, and then a new cycle starts. If this does not happen as well as period is missed then pregnancy test is required. However if you have doubt due to any reason can get blood test done serum hcg-beta.