Sex during fertile window

So this is the second time I’ve had sex with my partner (we’ve recently gotten together) and I told him I wasn’t on birth control so knowing that we both don’t want kids, common knowledge would be to pull out, right? We have sex and he finishes inside. Obviously I’m upset and I know the chances are high but I usually try to track my cycle through the app and use the withdrawal method and it’s worked fine for me all these years. But this is cutting it too close for me because my fertile window starts tomorrow, and my ovulation on this app says it’s in 6 days. I know the smart thing to do would be to take a plan b but I’d prefer not to and/or try holistic methods to prevent implantation. Has anyone had a similar experience to me?

Edit: yes, we’re both tested and clean