Pregnant? PLEASE HELP ASAP!!!!?

So here is the deal. My husband and I are TTC for #2. My period isnt due until the 19th. I am tired, been nauseated, urinating a lot more than usual. I took a test earlier today around 5 or 6 and there was a very very faint line of positive. I took another one about 45 minutes ago and absolutely no line. Do you think I am pregnant? Should I retest tomorrow morning? Or should I just go to the doctor and get a blood test? Please help. Any advise would be wonderful.