yeah im hoping so too. i never had that with #1 &2 so this is very new to me :( i seem to suffer more when im not active like sitting or laying it did orginally start waking in the night gasping for air and now its a day time thing too :(
Sorry I can't offer any insight since I've just had the typical squished lungs shortness of breath. But, since you have 2 already, I'm guessing you know how that feels, plus I haven't had any problem with lying down. I hope your midwife gives you some useful info at your appointment!
I had a bit of shortness of breath around 21 weeks but only for about five days and it was when I was laying down at night. Hmm, definitely speak to your midwife and I'm really sorry you're going through this. :(