When should i Test?

So my fiancé and i are trying for baby number two (his first my second) my app says that my period is suppose to come tomorrow but going by my average cycle being 28 days, i should’ve gotten it today. my app always tells me i’m suppose to get my period a day later. (i’ve tried fixing it in the app) so my period always comes 28 days after my last period, or a day early from what the app says. anyways, i took two tests over the weekend, one being a faint line and the second being a BFN. so should i wait until thursday if i don’t get my period tomorrow or should i test tomorrow morning?