2 periods in one?!

Has anyone experienced this lately?

I’m 24 and I’m super regular however I got my period again the day after having it end, so as soon as my first period ended my SO and I had sex and everything was normal that night, then the next morning I wake up and have a brand new period again except this time I have usually more clots than last period

Back story: I always have a 5-6 normal day cycle and it always comes on time every month so I’m very regular.

Has anyone gotten their period back to back?

How normal is this?

Also I’ve been working out and running more intensely (which I haven’t ran in about 3-4 years)