Okay, so I started using Nexplanon (implant in my arm) and its my first time using birth control. And my period is late by 3 days, could that be the side effect of the implant? Me and my boyfriend did have sex without a condom, but i did wait a week and a half after i got the implant to be safe. And he didn't cum inside me either. But I'm still concerned over the fact my period is late, last thing I want is to be pregnant. So I was wondering if its normal for the implant to mess up your period?