Is Pregnancy Possible If Fertomid Intake Is Skipped?

Hi doctor, I have been prescribed for fertomid by my gyena and to start using it on my 4 day of my menstrual but the problem is that I sometimes see my period for 3 days, and it also happend that during my 5 days of taking the tablets I forget to take them in a regular basis of that days, is there any chances to conceive even if I skipped a day without taking them, or should I double the next day, or extend to the 6th day.