implantation cramps

Hollster
Hey everyone
I was just wondering if anyone can help me with this question!
How soon after sex do implantation cramps occur? 
I had sex with my OH on Thursday and Friday which happened to be on my fertile days and yesterday and today I've had some terrible cramps in my lower stomach, I didn't think I'd get cramps this soon!!
Google is giving me conflicting answers 😔
If anyone can help me or shed any light on this I would be so grateful!!