Allergic?? So confused??

So recently I noticed that after I had alpro soy milk and soy yoghurt desserts I got this weird abdominal pain.

It happens every time I eat the yoghurts but happened for the first time after I had the milk today...

I’m vegetarian trying to go vegan and I’ve been eating stuff that contains soy my whole life.

Plus this has been happening directly after I eat the yoghurts for a while now and I’m sure it can’t be caused by anything else. But after I had the soy milk today I realised I could have a slight intolerance or allergy.

I’m not sure, let me know what you think,

P.s (I haven’t had any other symptoms apart from abdominal pains, no vomiting or diarrhoea or anything like that 😳🤢)