Helpp

So I was suppose to have my period on Monday February 18th however it never came on. Fast forward to later that day, due to it not coming on me and my bf decided to have sex for the first time in 2 years. The sex was unprotected. After we we’re finished we both realized he didn’t nut nor me which was ok because you know, NO PREGNANCY. The following day Tuesday February 19th I started to bled and the blood seem darker than usual. Of course I panicked but then it stayed on for five days which is a normal period for me. The blood was dark and light and was a medium/light flow. I got off my period that next Sunday. However, as soon as I got off I experienced cramps and a bit of mood swings. Could i be pregnant even though my period came on??