period pain like never before

Yesterday tea time I had bad stomach ache which I thought was period pain stood in my kitchen I tried to pass wind it ended up back firing and me running to the bathroom and then having a bath any way fast forward a few hours to bed time around 1am I was woken from my sleep with really really bad stomach ache I didn't want a repeat so I got up to go to the loo it wasn't that sort of belly ache this time it was period bellyache I can not remember a time I was in pain like I was last night apart from labour apart from last night it was constant I was crying and shaking it was so bad. My normal periods I have a tiny pain for an hour or so or nothing at all and only know I'm on AF when I go to the loo. Any one know any reason I could of been in so much pain. I ended up taking 4 paracetamol in 2 hours because the pain was so bad even they didn't work.