birth control + periods

hi! I was wondering if anyone had any knowledge or personal experience with this kind of situation lol. this is my first month on the pill and today was my first day taking the placebo. I‘ve been having sex since the first like 5 days of starting the birth control. we’ve been using a condom still and my boyfriend hasn’t finished in me. two days ago I had reallllly light bleeding (light red, almost pink) and a little bit of cramping so I assumed my period was coming and put a tampon in. I took it out a few hours later and it was totally blood free lol. then yesterday the exact same thing happened minus the cramping. today I haven’t had any bleeding or cramping but since I started taking the placebo pill I thought I was supposed to get my period today. idk if anyone knows what’s up with my body that’d be fantastic. thanks in advance lol