why am I bleeding

I was on bc for a year and I went off of it on December 28th and finished the pack. It's now January 12 I think and I woke up to red blood mixed in with pink and it's a medium flow. Is this normal it usually takes me 24 days to get my period. I had sex a few days ago but with a condom and he didn't cum. I'm going back on pills January 30th