My 19 year old daughter, who has been on the Depo Pravera injections for appx 12 months came home from a camping trip complaining of swollen and tender breasts, bloated (looking) belly, feeling a little sick with a weight gain of appx. 9lbs in about a week. After taking a ClearBlue Easy pregnancy test, the result was a very faint line in the negative. How accurate are these tests? Should she go to the O.B. for a blood test?