what is going on with my body

so i just recently last month started the mini pill, i will be starting my second month today but i haven't gotten my period yet and i'm not worried about it bc the pamphlet says it could cause irregular bleeding, etc. But then again it's so weird bc i'm supposed to be on my period right now and it feels exactly like i'm on it without the bleeding. Like i have a pressure in my butt like i have to poop but i don't, i have cramps & also when i'm on my period for the first two days my legs feel kind of numb i guess and that's what it feels like.. Could i technically be on my period without bleeding? I'm so confused but once again i'm not worried that i'm missing it I just want to know if anyone else has had this happen or anything similar?