Period Related Pain?

So this morning (this has also happened a few times in the past) I woke up with severe pain in my stomach (from my belly button to my bikini line). I spent 30 minutes on the toilet being semi constipated and dizzy and in absolute agony. Now I’m lying in bed, still feeling weak.

I start Aunt Flow in 2 or 3 days and I recall this happening around the same time last time.

What? Why? Help! 😭😭😭