7 days late

According to this app i had sex 2 days before ovulation and i started taking ovulation tests a little late this month so i don’t know if i missed when i ovulated but i am 7 days late now but tests have all come back negative... I’m typically always on time with my period or at most 2 days late but never 7 so I’m really not sure what to believe and then there’s the fact that I’m so nauseous and exhausted and i really just don’t know what to think... has anyone else had this happen? Did you end up being pregnant? Not sure what to do