Period Where Are You??

So This App Says I Am Suposse To Start For The 2nd Time This Month And The Day (30th) It said I Would Butttttt I Didnt But I Did Have The Worse Cramping In my LIFE!! i Also Had A Bladder Infection Too The 31st?? But My Period Hasnt Came So I Put On Here Is Was Late And It Says I Was Going To Start Today But I Havent... Does This App Have It All Wrong Or Should I Be Worried Becuz I Did Have Sex The 29 The First Time With A Condom But The second No.. I Heard If He Cums Once then When He Pre Cums I Can Still GetPregnant Cuz Of Left Over Sperm Im So Confused And Worried And I Dont Even Know Haha