Any chance???

Ok I've been trying too conceive for about 4 months now no luck😥😥. Yestrday I decided to give it another go Im in my fertile week ans yestrday it said there was a 33% chance. Me & my boyfriend did it for quite a while plus he was a lil rough. But after he finished i started crampin a lil bit and i have slight cramps today.. Has anyone had this happen too them or anything similar? Someone please helpÂ