Prego or Nexplanon?

I got on the Nexplanon about 2 months ago. Before I got the implant, I had the depo shot for 9 months. I was no ovulating and I got the implant when I was supposed to be getting another shot. During the week I had to wait for it to be fully effective, I had unprotected sex 2 times. I got the implant on a Wednesday, had sex and later took a plan b within 24 hours. I had sex again on a Wednesday and Thursday but Thursday I was technically protected. It’s been 2 months later and my breasts are slightly sore. I read somewhere that about 8 weeks in, your breasts would feel heavier and that your areolas might darken. My breast definitely have felt sore but they have not gotten darker. I highly doubt I am pregnant but are there any other ways to determine a pregnancy at 7-8 weeks?

Please no negative comments. I don’t necessarily have access to a pregnancy test right now.

Ps- the soreness comes and goes. For example, yesterday they were very sore when touched but today not so much. Still sore when I grab them hard but definitely do not hurt the way they did yesterday.

Thank you in advance.