Pregnancy scare

I know I'm probably just paranoid for no reason but please leave your thoughts!
I had sex the day after I ovulated. (This app said I had an 8% chance of getting pregnant) 
I used a condom and made sure everything was done right, me and my boyfriend are very strict about that. 
But idk why, I'm sooooo paranoid. 
How likely is it that I got pregnant? 
If I am, will my period that's supposed to come a week from now be normal, late, missed, etc?
Please tell me good things! I'm so scareddddd