My girlfriend takes Microgynon for PMS. Is it normal for her to experinece spotting?

Hello doctor,

My girlfriend has been taking Microgynon 30 for two months, with two packages back to back. She took Microgynon for suppressing severe PMS. The medicine successfully suppressed the PMS, but there seem to be some side effects. She experienced some spotting for a week, and the other doctor told me that it is normal for a microgynon-taker. Her actual period started the very next day after stoppage of spotting (which is late for two weeks), and it has been lasting for 18 days. In the beginning, the volume is lower than average, but red blood is visible.

In recent days, the volume keeps increasing, and it gets me worried about whether some issues are occurring. Should I take her to a gynecologist for a check-up or it is entirely reasonable for a microgynon-taker? We did not have any sexual intercourse before and in the case for an extremely rare accident, she took a pregnancy test, the result was negative. Therefore, pregnancy could be eliminated. She finished her second package of Microgynon around 6/4, and the next day, the blood volume started to increase. One more question, she has a third package of Microgynon and the gynecologist we saw said that she should begin the third package when the second period stops. Is this correct?