cramping after Ovulation

So I use the my days app and it said that I was starting in my fertile window sept 8. Glow says my fertile window started at day 10 and my peak was day 13. Well hubby and I only bd on sept 8... I'm sure by now I have ovulated. Now I am experiencing mild cramping in my lower abdomen. Could only bding on sept. 8 cause conception? We didn't do it on any green days according to Glow.