First time using this

Mrs. • Finally have our babies. R.I.P Kimara Jeffers. Welcome 2 handsome boys Allan and Kayden Jeffers. 👧🏾👼🏾👶🏾👶🏾👦🏾
Just brought this. My AF is tomorrow 5/7/15. (finger cross I don't see it) 
Should I take this now or tomorrow?