Can being around another female regulate your period?

I ve always had a regular period. My girlfriend, on the other hand, has not. While my cycle hardly ever deviates, she usually only gets a period every 2 or 3 months. I didn t expect us to synce up because of this, but it seems that we have. She s had a period 3 months in a row, which is unheard of, and I started the day after her this month. This has got me wondering if I m the cause of it. We all know that being around another woman a lot can change your cycle, but can it actually regulate an irregular one?