I think I am finally pregnant! WHEN SHOULD I TEST?!?

I normally have a 27/28day cycle. First period after IUD removal was Oct.28th Second was Nov.23rd. Third was Dec.20th Fourth was Jan.15th......As you see my period comes REGULARALY EVERY 27/28 days & always is here when I go to the bathroom first thing in the morning. NOTHING yesterday and NOTHING so far today...Should I go ahead & test?! I will be SO HAPPY if I finally get my BFP this month. Advise on when I should test please.....