Hello there I totally understand your pain. And I hope it is not.bothering you too much.
I cannot say it is common to have stomach ache while you have menstrual periods. But some women have this sort if condition sometimes. Do not worry there is surely solution for this. It is good that you are taking meftal spas for this but that should not exceeds more than 2 per day
And along with that you need apply hot pack to your tummy for relief. If you are having excessive bleeding along with pain then you need to consult a gyne for your assistance.
Mild to moderate pain during periods is common and its ok to take meftalspas for one or two days. But if it is severe get a pelvic ultrasound done to look for a condition called endometriosis. If you have endometriosis and severe pain you will require additional medications to control the disease.