weird cramps???

Carson
my period ended 4 days ago and since then I've had cramps/stomach aches that are really weird. 
my period was right on time and super regular flow. 
I had sex with a condom, he didn't cum, on the last day of my fertile window last month.
could this stomach pain be pregnancy symptoms or could it just be early ovulation. I don't feel sick at all except for my stomach so I don't think it's a virus.
I'm worried I'm pregnant even though I know the chances are extremely low.
any thoughts?