Very light & short period

F

My cycles were very regular but this month my period came 4 days late and only lasted one full day the day before and day after was very light, brown discharge. 6 days before my period started i had a small amount of pink spotting, which has also never happened before?? I'm really worried that some things wrong and it's preventing me from getting pregnant. I am not pregnant as done plenty tests to confirm that :(