h e l p

i had protected sex ( 20th of december and 1st of january). im 16 years old and after my last period i had 3 protected sex and i know that condom did not break, and plus he pulled out too. my period is not regular it can be around 28 and 36 days. today im 3 days late and i dont feel any symtoms ( fatique or craving back pain cramping or even spotting). im r e a l l y stressed that i could be pregnant. for how long should i wait do go to the doctor bc it happend couple of times that my period is late. pls, i need some kind of advice