I am 26 years old. I have very irregular periods. Meaning I have one about once a year. In 2016 I had one at the end of July and the same with this year, but this time it has last for 2 weeks and a day. It's very heavy with large clots. And cramps. Which is usually how it is when I do have one but it doesn't usually last this long. I have a doctor's appointment this week but it's at the end of the week. Should I be worried or is this about normal?