HELP! Positive and negative pregnancy test?!

I'm 1 week late today after having taken a Plan B last month after unprotected sex. Last month I also got an irregular period about 2 weeks after my last, but blamed it on the Plan B hormones. I've been feeling off a few days ago and took these this morning, to get 1 positive and 1 negative result. The positive is my first test.

How were your tests (positive/negatives) when you found out you were pregnant? I have 2 more to take tomorrow AM (I hear this is the best time, first thing in the morning).