Periods... its changed :s

I used to always get periods towards the end of the month, and never got period pains. And in the past 2 months I've been getting them at the start of the month and I'm getting period pains. It isn't my first year having a period it's my third or second,...

and all of a sudden it's changed. Is there a reason why it changed?

because of your food?

Hormones. Your body takes a while (anything from 2-5 years) after starting your period before it evens out. I didn't get period cramps until probably my third or fourth year into them, so don't worry. it's normal.