I believe BCPs can cause blood clots- not something you want to mess around with holding off about checking into, if the doctor thinks you may have one- they can be deadly.
I have done a lot of water I will try the salty snacks. It has gotten better but started back up again yesterday. Thanks for the advice. I may go to a clinic before my appointment just to check things out. The doctor scared me with the whole pulmunary embolism possibility due to my birth control pills but I don't think that's it. I'm very stubborn.
You should go into urgent care or the emergency room- they would likely put one of those oxygenation monitors on your finger & give you some oxygen. They will want to rule out life-threatening situations that can make one short of breath. It might help you breathe easier just to either get proper treatment if your life is in danger, or at least find out this lack of being able to get a deep breath is not being caused by something imminently life threatening as you wait for your August appointment.
Since it is a hot, hot Saturday and no-one has replied yet, .... are you sure you are not dehydrated or stressed out? I have shallow and slow breathing and sometimes, with pain or shock, find it hard to breathe deeply enough. More water and salty snacks regularly are what I have been advised. This is not a recommendation for you, but simply what seems to be helpful for me.