Getting blood work before a spay

So I had set up appointments to get my dog spayed with my vet which was quoted to be at the cheapest around $850 with blood work included. Then I just lost my job and can't afford all that but I was able to get a spot for low income at spay and neuter human society near me. With them they don't do any blood work before spay. So I'm wondering is it worth it to try and get her blood work somewhere before my appointment? She's year and half old and Healthy as far as I know, I'm just nervous about her being put under.