Thanks for writing.
use does not ensure that you would not get pregnant during their use.
Secondly multiple acts of intercourse at different times with use of i-pill only after one of the acts, does not ensure that you are protected from all unprotected acts.
Thus there is a high chance you may get pregnant.
Regesterone when stopped, periods occur within ten days. However if you get pregnant you wont menstruate even after stopping regesterone.
I-pill use does delay your periods or cause unexpected vaginal bleeding. However before assuming that the delay in period is due to i-pill use, you have to rule out pregnancy
by urine test.