Is this my period or implantation bleeding?

I was suppose to start my period this past Wednesday (it is Sunday currently) and I didn't start. on Friday I started having the spotty initial part of a period so I've been wearing tampons. I've been super duper light, barely even spotty since then. I stopped spotting yesterday, I actually forgot to put a tampon in all day and didn't even bleed. So like 1 day of super light bleeding. I've been TTC for a while now and actually had sex on my ovulation day this month but figured I'd just start my period like normal and not concieve. I took a pregnancy test Thursday and it was negative although. I've been feeling very nauseous. Like I pegged it off as cramps but it's not really cramps just nausea. Do y'all think I could be pregnant? Or think I'm just too hopeful.. Sorry for the long post I'm just curious