Abs workout during 2ww?

Yea or nay? I want to get my abs toned and have started Rodney Yee's yoga for abs but wonder if it will be safe during the 2ww? I hate not do so it then get a BFN and still not have toned abs but if it is harmful to a pregnancy or could prevent a pregnancy I want to avoid. Any thoughts? Anyone continuing their regular workouts until it's an official BFP?