Nexplanon and spotting

I got my nexplanon put in about two months ago. I have not had a period or spotting at all since getting it in. I have sex rarely but when I do we use condoms and my boyfriend pulls out with a condom. Anyways, I started spotting today and I know that some women experience spotting on the birth control. But is it normal for someone who hasnt had a period since they got it to start spotting?