Hi, I am 24 years old, 6 months pregnant with my second child and at a healthy weight. the last couple of weeks I have been short of breath after walking short distances, suddenly waking up in the middle of the night unable to take a decent breath and having lots of trouble breathing. The only way to get it to sort of subside is to slightly sit up on say a 45 degree angle. In the last couple of weeks I have started getting bad chest pains in the left side of my chest. Its almost like a squeezing pain and spreads up to my shoulder. My mum who is 57 has Cardiomyopathy and needs a transplant. Does this sound like normal pregnancy symptoms or is there a chance that my mums condition is hereditory?
Breathlessness can occur normally in pregnancy, it could be physiological with increase in uterine height.  Anemia can also cause this. But in your case I think its better get yourself check by your doctor as squeezing left side pain is not normal, moreover you have positive family history.