Is Severe Stomach Ache And Back Pain Normal During Periods?

I get bad cramps for the first two days of my periods. my father is a doctor, and he advised me to take spasmo proxyvon once only during the entire cycle, and that seems to be the only medicine so far that helps. i get bad stomach and lower back pain that usually remains over the first two days. otherwise my periods are very regular and is approximately 6 days long, the last day being negligible. i've been having periods since i was 9yrs old. can there be something serious?