So sorry to read of your loss and your fears.
I was very much in your shoes a while back....... wanted a girl with each pregnancy - I could just imagine myself as a girl mummy, then my firstborn was a son. With my second I thought that this had to be my little girl but alas, another little boy. I then also suffered a miscarriage and also told myself it must have been a girl but the next pregnancy WOULD be a girl. It was not.
When my youngest was born almost 2 months ago we went through a very difficult time (he was sickly, etc) and was diagnosed with Hirschsprung's Disease. He was operated on at 1 month of age and right now I'm sitting with him on my lap. You know what, I wouldn't change him for anything in the world or even a girl! Nothing I can say will ease your fears and if you happen to find out that it's another bouncy baby boy I have no doubt in my mind that you will love him like you love your other 2.
After our ordeal we have decided that our family is complete - and our family is perfect in every way. Yes, there's been stumbling blocks along the way, but at this moment in time I'm happy to have a little boy who is alive and who was a soldier from the word GO that I don't even find myself thinking of "what could've beens".
I hope that you are blessed with pink in your life, but if not, then rest assured that you'll be a queen in the eyes of 3 princes!
Good luck and take it easy on yourself!