scared of pregnancy

Me and my boyfriend had sex a day after my ovulation cycle ended, but we used a condom, the thing is that the condom got stuck in my vagina but not the ring only the rubber. I got scared even though I wasn’t sure if cum got inside i took a plan b 20 minutes after that happened. Now my period was supposed to come friday the 19th and it’s Wednesday the 24th and it’s still not here. Someone told me it’s because of the pill. Oh pd: i took 2 pregnancy test and it said im not pregnant but idk if i can trust that because i had sex only 12 days ago. So idk if i can trust it. Please help me be relieved