Thanks for your query.
If you have taken femilon consistently and correctly, there are very low chances of pregnancy
Also, remember that sometimes missed periods are common on pills.
As you have missed your routine period, please take a pregnancy test.
Continue taking the pills as advised without a gap if the test is negative.
Also, if this pattern is routine ( pattern of delayed cycles ) consult a gynecologist to rule out causes like thyroid
hormone disturbance, polycystic ovaries
, endometrial hyperplasia
All the best.