pregnancy tests

I Took a Clearblue Pregnancy Test and It Was Positive, But Then I Took Three First Response Tests and They All Were Negative: Advice?

I Took a Clearblue Pregnancy Test and It Was Positive, But Then I Took Three First Response Tests and They All Were Negative: Advice?

A mom writes in asking for advice about pregnancy tests. She says she took a Clearblue brand pregnancy test, and it was positive, indicating that she is pregnant. She then took three First Response pregnancy tests, and all three results were negative. This mom is confused and wondering what she should do. Should she believe one brand of pregnancy test over the other?