Weird cycle

Liela

I’m really confused because I am suppose to get my period on the 30th of June. Its never early never late. Well today (15th) I got cramps and light bleeding and I don’t know why. Yesterday I had back pain and headaches as well (normal period symptoms) but there isn’t much blood and I don’t know why it’s early. I’m not on any birth control and I’ve never had sex before.