Late period?

So, on December 3 I got an implant in my arm. My doctor told me to take the last two weeks of my birth control pill before stopping it forever. During that time I had sex with my boyfriend twice and he came in me both times. Usually I get my period on Tuesday or Wednesday but I haven’t yet. I’m having a lot of symptoms like I’m about to have my period/ on it but I’m not bleeding. I’m pretty sure I’m safe and not pregnant but idk why I am late? Is it the implant or is there anyway I could be pregnant?