ovarian cysts

people that have/had ovarian cysts before can you inform me on symptoms and causes? my period is around 7-9 days late and same thing with my last period and i’m getting bad cramps, which i don’t normally get with my period, and i’m never usually late. i usually get it a couple days or a week early. i’m having middle back pain and then it goes down to my back. it’s not bad but it comes and goes and it is uncomfortable. i’ve also been getting pain in my upper thigh, and my boobs are very sore. i don’t know if this is caused from anything but at this point that’s what makes sense to me.