3-4dpo

Ok so I've been trying for 3 months. I wasn't in a rush so I was only using the calendar method. when I got my AF last month I was disappointed so I bought clear blue digital ovulation test. Ends up the calender was way off. I got a positive opk after my fertile window. (Oct 18) so of course we baby danced that day. on the 20th I was so sick... throwing up, it went away. Today is the 22nd and I'm having cramping in my lower right abdomen. Could this be implantation ? Can it happen this early ? I know it's way to early to test I'm trying not to. Also my breast are sensitive. and I'm waking up at night to urinate I've never done that I don't even go to the washroom when I first wake up.