Concern

I had sex like over a month ago. I took a pregnancy test and it came out negative. I also feel sick sometimes and i have stomach aches, i did get a period from the 19-24 last month and im expected to start my period tomorrow according to the app. Last time my period was late like 4 days according to the app. So should i be scared about my period this month if i dont get it tomorrow or should i take another test?