Is it safe to drive after getting blood drawn?

I have to get blood drawn from Quest Diagnostics just to check for different issues that would be important to know for pregnancy (like if I'm anemic, have an std etc) I think I remember my midwife saying either 5 or 8 vials. Do you know if it's safe to drive after that amount of blood is taken? I'm 18 weeks pregnant. I know the nurse will let me know when I go, but I would like to know in advance because I have to drive by myself and I don't want to get stranded. I get light headed very easily if that matters at all. Thanks ahead of time!