Bad Day!

I'm not feeling well today because of the pain cause by my dysmenorrhea.Yesterday i tried to go to work but on my way,i couldn't do it.I felt like I'm going to collapse.I went back home to lay down.I took medicine then rest for a while.After an hour i recover from the hurts that I've been through.
Until now I've been wondering why only woman can experience like this every month?Why only woman get pregnant and deliver a baby?
I should rather asked God WHY?