Period pain

I woke up this morning (5:30am) with the WORST cramps I have ever had in my life... I it honestly felt like I was being stabbed repeatedly... it hurt so badly that I had to run to the bathroom to throw up... now my period was 10 days late and I just started taking my birth control pills... does anyone know why the pain was so bad?? Or have experienced the same thing?? My period hasn’t been heavy this month ether... any help would be great!