Where's my period?

Cindy • 20 year old FTM. Mother to a previous baby boy, Adonis👶🏻💙 Born at exactly 42 weeks on June 24, 2015. 8:23pm.👪❤️
Hi everyone! I had my first baby June 24, 2015. I'm a breast feeding mom. I got my iud (mirena) in October. Had my first period (after giving birth) on December 2-7. Was supposed to get my period on Jan 4, but still no sign of it... Has anyone gone through anything similar or know what's going on? Please share your opinions, thanks!