Could I not be pregnant

After my second to last day on my period my boyfriend an I had sex an he released in me we kept having sex the next three days an all those days he released in me an around that time I was “fertile” it’s been a week an some days an my period is supposed to come on the 24 but Ive been thinking the only high chance of being pregnant is when ovulation is occuring but could it be possible I am pregnant?