So confused..

I had a positive ovulation test on 10/27. DTD a couple times during my fertile week but not every day. I've had gas, constipation, weird pain in nipples, lower back ache, headaches the past two days, thrown up twice, and creamy cm. Aunt flow was due 11/11 so this will be day three late with no signs of her showing. First response test Monday was negative. Is it possible i didn't actually ovulate and opt was wrong? I don't get this..