Discharge?

Hi ladies, I might be overthinking this, but I’d really like to put my mind at ease.

I had sex on Saturday (11/23). We used a condom and I have the Skyla IUD. He did not pull out.

It hurt a little at first since we haven’t had sex in a few months (busy with college and work), but other than that it was good.

However, it was during my predicted fertile window. And today (11/27) I noticed a tiny bit of brown discharge. I’m like 5 days away from my period. And I was cramping so bad yesterday.

Could it have been from sex Saturday? Maybe too rough? Ovulation? Just IUD? Or period? Hopefully I’m not pregnant, I don’t believe the condom broke.

Not really worrying, just confused and curious. Thank you!