finishing in during fertile days could the seed be planted

So I ended up having sex with my ex 6 days after I finished my period, I'm usually good with protection but we had a couple drinks and I know he finished in me. I'd say I'm sexually active for the most part but that night I know he finished in me and now I'm wondering what the chances of being pregnant are 😳😳😳 any input on that guys ? I have taken one test and it was negative so I'm waiting until next week to take the other