Totally confused

Nicole
So I've been have back pain and abdominal cramping from Sunday thru this morning. It was the same exact feeling I get the first day of my period every single month. This lasted for a few days and no period. I'm actually due to start tomorrow 2-12-16. Well last night my husband asked me to take a pregnancy test. I took 3 and we saw faint lines on all 3. I'll include pics. Well we just left immediate care. They ran a urine test as well and said they didn't get a positive. They said negative. We are so confused. Does anyone have any advise?