I understand your concern.
Periods may become irregular after the morning after pill. Sometimes the periods may come early or sometimes they may get delayed. However if delayed beyond a week of the due date pregnancy
is a possibility. It seems your tests have been done too early. I advise that you repeat them after 3-4 weeks of the after pills.
However if you are breast feeding, it itself causes irregular periods
. In that case just repeat the test after 3 weeks and if negative, do not worry.
Hope I was able to help you.
Thanks for the question and for using HCM.