Thanks for writing.
Any unprotected intercourse
can result in pregnancy
So ruling out pregnancy is a must. You can do home urine pregnancy test.
If it is negative, then the other possibility is the delay in you period which has occurred due to improper use of pills.
Missing birth control pills can result in pregnancy as well as have an impact on your periods.
They can cause unexpected vaginal bleeding, spotting and irregular periods
Also during the initial 3 months of use of birth control pills , side effects like irregular bleeding, spotting, nausea
, breast tenderness can be seen.
You may change the pill if your side effects persist for 3 months.
Also to ensure proper effect of pills, they have to be taken on a fixed time without any delays or missing as then they cause more side effects than benefits.