Confused and Scared

Plz help, ive only just started having sex with my boyfriend about 2 months ago, we’ve used condoms everytime but i missed my period last month and im really nervous incase i dont have one this month. i took a pregnancy test and it went negative straight away, although tests these days are almost always accurate im still worried. why have i not had a period? is it because iv lost my virginity @ 14? or does everyone have that symptom if they are consistanly sexually active? could i be pregnant, please help, im so confused!