Cycle day 47 no AF or postive prego test but had spotting last night then none this morning? Just a little tmi.

Hello Need some help, today makes 16 days late for AF and i just now had spotting a little brown then wiped to very light pink last night. (I thought AF my be showing up for the fact i haven't had any positive blood or urine test.) I put panty liners on just in case before i went to bed and i woke up with nothing. I normally have a 31 day cycle and everything is on time, maybe a week late at the longest. Could i have ovulated late then delayed my period but still turned out to be pregnant and just just now having implantation bleeding. It sounds like im over complicating things but just trying to understand why i would be just spotting so randomly. This has never happened to me before. I was irregular when i was a teen and right before my 20s but have been regular for a long while now. Ive also never had spotting between periods either so to me the only thing that everything is pointing to is pregnancy but all test says no. My first pregnancy was very easy and didnt take this long before i got a positive and heard a heart beat at 6 weeks and was very strong. Can anyone help me?