Anything is possible exspecially if he went inside of u , take a test. My husband NEVER went inside me and we barely have sex and im pregnant.
It's quite possible to get pregnant 4 days after the last day if your period, if the sex was unprotected. In fact it's a good time to try for a pregnancy. It does not matter if you were tired or had traveled a long journey that day or if you were home all day resting.
If you had sex yes it is possible.