Hi, I've been having periods since I was 11, and have not been regular for more than three months at a time. I'm 18 now, and since then, my periods are few and far between. The longest I've been without a period was 11 months. Now I'll usually go 2 to 4 months between periods. My flow is usually quite heavy, but sometimes, it is very light but very dark brown in color. I am starting to get worried about this, seeing as after 7 years, I would think my cycle would normal out. What do I do? Is there something I should be tested for? I have heard that problems like this can lead to infertility later on and I definitely don't want that to happen, any and all advice or hypotheses would be helpful. Thank You.