Hi all! I'm 20, sexually active. I've had a period since I was about 10 years old and about 4 months ago, I started seeing changes in my cycle. Usually, I'm 24 days on the dot. But now I'm always either 2 days late, 2 days early, etc. Why the sudden change? I haven't been working out more, I'm not stressed out that I know of, nothing is really different at all.