Advice please

Morgan
I am 18 years old and back in October I got off the depo shot after being on it for 2 and a half years. Ever since my period has been pretty regular. But I have took 7 pregnancy tests all with negative results and I am 12 days late. I have even went to the health department and I tested negative there. I have a blood test scheduled for Monday and I will be 2 weeks late then. Has this ever happened to anybody? I am wondering if maybe the depo shot has screwed with my hormones and that's why I'm not coming up pregnant or if maybe I am just really not. I have also been having morning sickness and sore breasts. It is killing me not knowing because me and my husband have been trying. I am really wanting to get pregnant but I'm afraid to get my hopes up. Any advice or knowledge about this would be greatly appreciated