Hi Doctor, I have started taking femilon from the first day of my periods. Can we participate in sex from the 4th day onwards after bleeding stops without using any condoms. Is safe? Please answer

No you need to take it an entire cycle before they are fully effective.
If you miss one pill or if you take it over 12 hours late, you need to use a backup method for the next week.

Also even as taken exactly correct there is still a 1 percent chance of falure. So pregnancy can still happen taking this or any birth control pills