For 7 years, my period has been exactly the same. A few days late, I feel swollen the first few hours, first two days are super heavy, and it lasts five days. I also would eat a lot less. Then about 6 months ago, my period started getting really irregular and I never knew what to expect. Now, for the second month in a row, it started RIGHT on time, I was not swollen, I've been super hungry, the flow was light, and it only lasted three days. Is it normal for a period to change like this after 7 years of regularity?