Help, should I be worried

Hi ladies, I skipped my period this month, I was supposed to get it 12/29, and with the skipping I was due to get it 1/19. I woke up this morning to dark brown spotting all over my underwear. Is this just because I skipped and it’s breakthrough bleeding? Should I be concerned? I haven’t had sex since New Years eve but now I have cramping and the spotting so I’m just wondering if it’s probably breakthrough from skipping or if I should be concerned and take a test. Thanks !! Also i’m on Junel Fe