Help please, am i protected?

Ashley

I used to be on the birth control patch called xulane on my period free week (which is my period week) on my 3rd day of my period i switched to the nexplanon implant. I’ve had it in for 8 days, on my 8th day i had unprotected sex with my Bf and i believe some ejaculation got inside me. Will i be okay? My dr told me not to have unprotected sex for 3 weeks but I’m not sure if that was just a precaution or if i could actually possibly get pregnant if i did. Please help I’ve heard many people say 7 days you’re protected and others say up to a month