Question for my ladies

yaya

I’m considering switching to something different for my birth control because I have a hard time remembering to take it, and to refill it, so I forgot to take it for 4 days straight, I did take it all the day I did remember and I was on my period, now I’m still bleeding but it’s light like a pink color, so my question is, I had sex unprotected, on Saturday night, why am I still bleeding?? Is it because I took my pills late?