help?

I’ve had Nexplanon (implant) since February of this year and it has never caused me issues. however, a few days ago, i noticed that my boobs are slightly sore and since I’m sexually active, my first thought was pregnancy 🤦🏻‍♀️ My boyfriend and I are both 19. I’m on Nexplanon, we always use a condom, and he also never finishes in me (I know pulling out isn’t a real birth control method but it may be worth noting). My periods are irregular anyway, coming about one every 3 months, so I can’t really base anything off of if I’m late or not. Am I just psyching myself out and do I have nothing to worry about??

i would reply and upvote responses but i want to stay anonymous so thank you in advance 😊