worried about pregnancy 😔

I have to stop stressing but I can't. Before I hear the oh you should of wore a condom your not on the pill why didn't you take plan b shit happens. I have irregular periods but after me and my boyfriend had sex I took a opk to make sure I was not ovulating cause I know if you don't ovulate you won't get pregnant and the opk test was positive two dark lines. He also came in me. It's to late for plan b I'm freaking out I don't know what to do I'm so stupid 😔 But there's not always a chance right? If I am pregnant it will be a challenge but I will keep the baby