Could something be wrong?

Me

So, my periods are usually very regular, last about 6-7 days and my flow is only heavy on the first day. This month I was 5 days late and I’m now on the fourth day and my flow is so heavy I’m using about 5-6 super tampons in one day when I usually only use 3. Also I’ve been having horrible cramps. I don’t have medical so I don’t want to have to go to the doctor unless it could be serious, is this normal?