Faint lines then negatives. Help would be nice

I got a faint line last week on clear blue and then tested few.days later twice and everything is negative. Could I be having a miscarriage or could I still be pregnant? I've been through so many it just kills me to think of going through the same thing. Have had back pains since Thursday off and on, boobs were kinda sore now they're not at all, feel like going to start, no period week late. Anyone else experience this but pregnancy went full term? I just want a little hope