Aww, 26 weeks can already feel so uncomfortable, especially when you're chasing after another child too ❤️
The breathlessness is also pretty common as your growing uterus starts pushing up against your diaphragm, although it's always worth mentioning it to your OB, especially if it's severe, happens at rest, or comes with chest pain, palpitations, or dizziness.
Hang in there, mama. Take things one week at a time, rest whenever you can, and don't hesitate to bring it up at your next checkup if the breathlessness or fatigue feels worse than expected.