Extra period thing?

Lily

So I finished my period like 3 days ago and I have a very regular cycle so I’ve started another period and idk it seems too early for me to have synced up to someone else’s period and i did the worst thing possible but I looked it up on google and it said I’m either pregnant, literally zero chance (I’m still a virgin rip) or I have an sti (again, Virgin.) or I could have ovarian cysts and I have a family history or ovarian cysts so I’m kind of freaking out but I was wondering if this was common or? Idk.

I was wondering if this happened to anyone before or if I should go to my gp and ask them about it but I’m panicking rip.