Nexplanon implant

I got my implant last week on Wednesday December 28th 2017 at planned Parenthood and was told to use condoms for 7 days due to the fact they put my implant in a day before my ovulation time... 24 hours later I had unprotected sex , i know it was kind of stupid to do the opposite of what the doctors said but I’m supposed to get my period January 3rd which is today and it hasn’t came 🙄 I think it’s because of birth control but I’m also thinking its pregnancy... can I have some advice on what to do or anyone been through this before?