I'm not entirely sure this is normal?!?

Ok so normally I don't get a whole lot of cramps before my period and I most definitely don't get back pain. But I have been cramping and my back has been sore and hurting for three days and I'm physically exhausted. My lower stomach is all swollen too but I'm not on my period. According to this app I was supposed to get it on Sunday, but I've only been using this app for around two months. This is just unusual for my body so I'm just worried This is normal though right? Even if this never happens typically happens to me before my period.