How long does your menstrual cycle last (when it comes)

[Rafferty]

My cycles are 28-29 days. My periods have been getting longer it seems. I think they are between 8-10 days...10 days this month. I'm starting to worry that something is wrong. They aren't heavy, only heavy days CD2 and CD3, then light, and spotty. And then this month day 9 suddenly was heavy in the morning, and back to spotting. Should I be worried? When I look online long periods are signs of problems. I barely have cramps, didn't even take Ibuprofin this month, and I'm very regular.