I Am 22 Years Old. I Usually Have A Menstrual

I am 22 years old. I usually have a menstrual for 3-4 days. Well it's that time and I'm going on day 11 and it's very very light and I have no bloating, cramps, dehydration nothing it doesn't even feel like I'm on it. I'm starting to get concerned because this has never happen. I've mostly been 3-4 days no longest I've ever had was 6 days.