Cramps when your on the mini pill?

Lexi
So I've taking the mini pill for the last three months and this month my period is three weeks late (I haven't had sex so I'm not pregnant) and I'm having light cramps the last few days and now I'm getting really bad cramps like I do on the first day of my period, but I'm not on my period. I'm starting to get concerned. Has this happened to anyone else? If so please tell me. Thank you