Exuasted going up stairs...

I'm only 21 and can barley make it up stairs.. Were talking only like 20-30 steps... That's not a lot... I feel my heart racing and I breath very heavy as if I just ran 2 miles or something, my face turns red and I can feel my chest thumping... I'm a big girl but not that bad, 190 pounds.. Still 20 steps?? Can my weight be why?... And I am 11 weeks pregnant but I was having this problem before I got pregnant but it has escalated a little... Im getting really concerned, also if I walk around for a long period of time I bloat up like a balloon and eventually it hurts to walk and move my body around so I have to sit... I just feel really weak and this just doesn't seem right, especially for my age, what if I'm to weak to deliver this baby? Im worried...Is anyone else having the same problems... 😞