Could I be pregnant

So I’m 19 years old and just about 3 months ago got the nexplanon implant put in. The first few weeks everything was fine but then I noticed that when I felt my upper arm that the bar did not feel right because I’ve been on the bar before and it was the first time I’ve had a problem with it. So I called my dr and they said nothing is wrong with it so I let it go. But my period started messing up for a month straight I was on and off my period. I recently went to the dr again and they told me that the bar is not releasing any of the hormones that help prevent pregnancy and they told me that I’ve been on birth control for too long and they think I’m becoming immune to birth control. I’ve been on birth control nonstop since I was 8 and they think it’s an issue. Well for the last few weeks I’ve been feeling sick and a lot of people are telling me it sounds like I’m pregnant with all the symptoms I’ve described but I don’t know what to think and me and my partner don’t use condoms because we hate them and well I’m on birth control so what’s the point so is there any chance at all that I may be pregnant???!!!