Implantation dip or AF on her way?

Co

Last cycle my temperature started slowly dropping on 12 DPO. I'm 10 DPO now and had a half degree drop this morning. I'm on my second round of clomid and my husband's birthday is in 2 days. I'd love to give him a positive as a surprise! What do you ladies think? Implantation or AF is on her way?