Fainting during blood draw. 😭 Advice?

I had my first appointment today for my second sweet baby. I've always had low-ish blood pressure while pregnant, and today I fainted during my blood draw. TWICE. During AND after. 😫 
After the first time, I asked the guy if I had fallen asleep. 😂 The second time was much less pleasant and more terrifying. I'm feeling a little traumatized. 
Any advice on how to keep that from happening? I was thinking maybe I should eat something really salty before I go in. I have another draw in a week and a half. 
But look at that precious nugget!😍