One positive, two negatives

Anna • 27 💁🏻 Married 5/23/15 👫💍 One baby girl born May 2018. 👧🏻
I have been having some slight pregnancy symptoms (gas, achy back, exhaustion) so even though my period isn't due for a couple more days, I decided to test this morning. First test was positive! :D Second line came up right away. I wanted to make sure I wasn't trippin so I put two more tests in the SAME urine (peed in a cup) and used SAME brand tests and both were negative :( so now I don't know if I'm pregnant or not. Any thoughts?