Tomo Microvlar right and always regulated, but delayed?

Good afternoon, Doctor. My girlfriend has always had a regular cycle, and she already takes the Microvlar to 4 years under medical supervision. He forgot none and took them all at the right time. During this time, she took Paracetamol, Ginseng, Dorflex and Diclofenac of Potassium 50 MG. For what I sought information, do not interfere ... am I correct? However her menstruation is 5 days late, but she feels cramps, body pain, headache, but nothing came down. Can contraception fail?
Expert answer:

The contraceptive may fail, but this is rare for those who take it right. Most likely in her case is a menstrual delay due to hormonal changes (very common) as it is going down and does not go down she ends up feeling all these pains, probably menstruation should come down in the coming days.