Digital pregnancy test; maybe something you didn't know...

I was supposed to be 3w 2d and I took a digital test. It showed 3+ which was a great sign. Well a few days later I had an extra one laying around and decided to test again. It showed 2-3. At first I was concerned but convinced myself it was because urine was not concentrated enough. So the next morning I used my last one, (I had a pack of 3). It says.... 1-2. I completely freaked. I called my doctor and he got me in right away. After getting my labs back amd an ultrasound I was having an ectopic pregnancy. It was a very sad and difficult time.