Weird period?

So my period started a day early which is very unusual. It’s also been very light (like I can almost wear just a panty liner and be fine light) which is also slightly unusual. It’s been all brown/ old blood, I only saw some pinkish/ red blood once. I’m on birth control but did miss a pill this month. I’m worried that it’s implantation bleeding and not my period but idk if I’m being paranoid. Any thoughts?