We eat pineapple here all the time as part of our normal diet, dr has never told me not to, and i spent most of my pregnancy in the high risk ward in hospital where it was often served for desert with custard, so I don't think its the pineapple causing pain but maybe you have food poisoning? Best to get any unusual pains checked out. Good luck!
I think pineapple is a natural laxative so it might be your stomach and intestines that are cramping up. Just this past week ive notice if i eat certain foods i get horrible stomach/intestinal cramps. Im 22 weeks.
I've heard pineapple makes you go into labour...
Pineapple contains the enzyme bromelain, which is thought to help soften your cervix and bring on labour. Eating large amounts will probably stimulate your tummy, which could also stimulate your womb.
If you're worried ring a doctor x