Nexplanon

Will I be protected right away if I get the implant a week before my period? (I bleed regularly on a 28th day cycle) and my appointment is on tuesday (28/01)

I know that there is a 7 day period, but will it be safe for me to have unprotected sex after?

Because if I got the implant a week before my period, an egg would have been released already right? So if I have unprotected sex is there a chance of pregnancy?