My period ended on the 13th of jan 2022. my boyfriend and i had unprotected sex on the 15th. he ejaculated outside of me. but is there a chance i could be pregnant?

The fact is that there is no "safe' time that you can have sex without using contraception--there is always a chance that you can conceive. There are "fertile" times in the menstrual cycle that are most conducive of conceiving. 2 days after your period is not in the fertile period, so the chance is less but camnnot be ruled out

If he ejaculated outside than chances are near 0