Freaking out to the max!

Caitlyne • Bonus mom to 2💜💙 Bio mom to 1 💜
So my baby daddy and I aren't dating, but he's living with me until he gets his own place (goal is end of October) 
When we broke up, (he ended it) he right away started having a thing with his ex girlfriend. 
He claims they had sex the day we broke up (I'm still not sure he didn't cheat but w/e) 
He's now dating her, officially. 
I just took a bath and went into his drawer to grab one of his sweaters to wear as its cold as hell here and my rooms downstairs and I was lazy 😂. 
I find a pregnancy test... A first response digital test... 
I realize after a few seconds I never took a FR digital... Only first response and a clear blue dating one... 
The result had been off the screen but it was definitely used... But because they don't last forever on the screen, I don't know what the result was... If now both of us are pregnant...
I know it's not officially my business, but I feel like I also deserve to know... 
I'm having his child who, if she's pregnant, will only be a few months older. 
I can't help but be hurt, and pissed and confused and just everything at once. I don't know what to feel or how to react... 
Should I bring it up? Or pretend I saw nothing? 
We're very young. He's only 18... (I'm 17) 
I believe his new girlfriend is 19. 
I'm so overwhelmed right now!! (Please no telling me to kick him out or anything. We're still good friends even though half the time I would love to punch him in the face xD 
Just want advice on how to approach this situation) 
Pictures below is the test