Heavy periods and clots

I have been on Loestrin 24 for about 2 years now. I am 38 years old. I love the fact that my periods were 1-3 days long and were not heavy at all. I once skipped a month and my doctor told me that was normal. The past 2 periods have been anything but normal for me. Last month my period started a day early and lasted for 7 days total. I haven't had a period like that since before using birth control. This month my period started on time but the amount of blood and clots I have passed is beyond the norm. I know it's normal to pass clots, but I thought that while on Loestrin it was supposed to be very light. I am very good at taking the pills everyday and at the same time. I have an appointment with my gyn in a few weeks, but I was just wondering if anyone else out there has had the same symptoms as me. it would put my mind at ease and I won't feel as if I am getting old and possibly going through changes of some sort.