HELP PLEASE hcg45?

Carley
Ok I have taken several pregnancy tests all positive. I was at the hospital last night and they did a blood test my level was only 45. I have not missed a period yet (due tomorrow) I'm really worried because my nurse said it may not stick because of the low number. I think I'm 12dpo maybe 13. Has ANYONE experienced this and had a healthy pregnancy? This is my 1st