false positive?

So this morning I got up, and took a pregnancy test (Clear Blue with the lines) i took it put it down, and took a 5 min shower. When I came out it was postive. But because my husband, and I have been trying since November 2015 I went to the store, and got a more expensive clear blue test. The one that actually says pregnant, or not pregnant. Well it came up not pregnant... I have one more test that I can take, But was the first one a false positive? I been tho thats very rare...