Pregnant right before period 🤔

Okay so here’s the situation. My bf and I BD the entire weekend of Mother’s Day, my period was due on the 19th and came but extremely lighter than normal. I Normally have a 6-7 day cycle and pretty heavy. It lasted 3 days and everyday I was able to wear just a panty liner (didn’t fully saturate those either) this has never happened to me before. Anyone had this happen to them?