ovulated early please help

so I have a lot of kids. Im ovulating and he didnt pull out and said he would. plan b does NOT work. i have got pregannt b4 on that and theres a study about that NOT working while ovulating. it can actually help get you preg. so what are other ways before i stop ovulating to try to stop from getting pregnant? my body really needs a break. even natural things i can do? anything or even right after ovulation? i dont want to give another up for adoption. please