it is normal. usually by 32 weeks it gets easier to breathe since baby sits lower. i barely could breathe with this one until early 30 weeks and it felt like a panic attack for me.
I'm 13 weeks also and breath heavy too my bf be like calm down lol what's wrong with u in a jokingly way and I'm like idk I guess I'm just getting fatter that's what I really thought lol I'm a ftm so I'm still learning
I started short walks daily to help with my breathing. I breath extremely heavy and I'm only 13 weeks. If your baby is that high he/she is compression your chest. That's why you breath so hard.