Has anyone experienced a period like this before?

Days 1-3 super light. Days 4-5 heavy (what you’d normally expect for like day 2). This seems backwards! I’d love to hear from others who HAVE experienced this. & curious if maybe you had a hormonal issue, have PCOS and/or endometriosis, etc.

*I know periods differ from one to the other and various things can change it. But has anyone HAD this experience and found out what caused it? This is now my second period like this, and it’s not my normal. I’m not too concerned just genuinely curious. I meet with my OB soon and will discuss.