Can you get pregnant on Nexplanon?

I have the nexplanon implant since January of this year. I have three kids already, age 6, 2, and almost 1. I’ve been having some symptoms that I’m not sure if are caused by the nexplanon or if I’m pregnant. I can’t get a test yet to check ad I don’t drive and haven’t been to the store. Last night I woke up out of a dead sleep ready to puke, my mouth was full of saliva, and I almost threw up on my husband. Today I woke up with full, sore breasts. I am still breastfeeding my little one, but I never wake up full. I haven’t had a period since March, and I know nexplanon can stop periods for some people. I’ve also been a bit moody and have had headaches most days. Back in April, I had mastitis in my breast and was given an antibiotic to take for ten days. The doctor said it should be fine with my birth control, but I recently looked online and saw some doctors say it can decrease effectiveness, while others say it won’t affect it at all. So has anyone gotten pregnant on the nexplanon, or am I just freaking myself out for no reason? Thank you