Hiya Sammy,
Just my personal input on these questions, not in a medically diagnostic way.
My blood pressure was never a problem as far as I knew. Having said that I had a massive heart attack and that was followed about 5 months later by a smaller one. 6 weeks after that I had a triple bypass - only one of my arteries were working 20%.
Any upper body physical exercise might bring on burping. Taking air in and out as you work out. Any type of gastric problem may cause this.
I would seriously recommend though that you see you GP about your worries. What is true for one might not be true for another. You cannot afford to wait around if you suspect anything like this at all.
Hope you are ok at the moment.
goldenwings