I used to get terrible period pains, they started a week before my period was due and lasted for the whole period. I often spent nearly two weeks in bed as a result, out of my head on extremely strong painkillers that had little effect.
However, after three years of really intensive treatment - a combination of surgical and medical (drugs) - and finally a successful pregnancy, my periods became nearly pain free. The first time this happened I was so surprised I went to my gynaecologist to find out what was wrong! Periods shouldn't be painful - pain wherever it is found is a signal that something is wrong. If you do get really painful periods then you should have them investigated and treated. Menstruation is something the female body is designed to do and it should be able to do it without pain.
I used to get awful period pain - I would be in pain for a day or two before my period and then the first 2 days at least. These days I tend to get emotional symptoms (I cried during the Croods where Eep says good-bye to her dad lol) but minimal pain.