Hi Miriam. What gave it away was feeling like I was being jabbed with a knitting needle lower back about 10dpo. Lots of gas making me burp, and I never get that,( sorry tmi). I tried to drink mulled wine on boxing day and thought I may throw up. Lack of interest in most food. The real tale tale, I normally spot 11 days into leutel phase and there was no cm at all and still none now. I had feeling af was coming for about 3 days also. Sorry last one kept waking up with sore throat. At lot of my symptoms were very similar to af coming.
Try the vits if you havn't already it's the only thing we did different. I took them for two months whilst we were not trying ( teacher didn't want august baby) then first month of trying on them it happened!