I'm breastfeeding my 18 month old still and I took am ovulation test and we had sex when I got a peak reading. I had bad backaches a week after peak fertility and nausea. It's five days after I should have gotten AF and still just BFN. I'm breastfeeding so my periods are irregular. Has anyone experienced the same and should I stop breastfeeding to get my periods regular. I will be 35 in August. Thank you for any advice or experience!