Pain/crampy feeling

Sam❣️
I'm not sure if this is the right group. But I started my period on 8-28/8-30. 8-30 was my last day I took my b/c pill. On 9-8/9-10 I started my period again I guess from ending my b/c idk but the last few days I've have horrible crampy feeling/pain and I'm not sure why? Any ideas?