Bad Period cramping

I took plan b a little over a week ago, I had just come off my period a few days before that and yesterday I got my period again, the cramping is horrible. I am cramping clear into my hips I am a small person so maybe this is why but I never get bad cramps like this. I don't take medicine bc they usually effect me so I don't like to, what can I do for this and is this normal for a period after plan b, will this continue to be what my periods are like now😬 ?