should I be concerned?

so I'm supposed to start my period today, but it hasn't came yet. usually like three days before my period starts my tits will hurt and I'll get some sort of cramps. this month my tits don't hurt and I'm ridiculously nauseous and I'm really tired all the time. my bf came in me while I was just coming off of my period and I'm worried that I might be pregnant..I don't wanna take a test till I'm at least 4 days late cuz I know it can be late a day or two..should I be stressing it?