It'd an old wives tale that eating fresh pineapple can help bring on labour because of a chemical in it but in actual fact you would have to eat like 30 pineapples including the hard bitter core (that's where most of the chemical is) for it to have even a slight chance of working. Eating that much would probably make you sick anyway. Also tinned pineapple would not work anyway as the preserving process gets rid of the chemical and wouldn't have the core part anyway.
It's probably just growing pains, I'm now 37 weeks and I went through several growing phases where I had some stomach pain.
Hope this helps ease your mind x
Nothing will happen if you eat pineapple, just be careful with how much you eat, it can give you the trots lol.
Thank you for the feedback I really appreciate:)
I would be careful of the BPA laced cans. Always choose BPA Free cans.