freaking out slightly 😬

So my birth control "period pills" started last Thursday and I typically start that following Monday. I havent started yet and I spotted some yesterday. (Sunday). I don't know if I should get a pregnancy test or if I'm just freaking out for no reason. Ever since I've started my birth control, I've been right on the Monday after starting my green pills. This has never happened to me before.  I could be overthinking but I'm not sure. What do you guys think? Should I buy a test or wait? I only have 2 period pills left after I take today's...