Help!!!

Ladies , not sure if anyone could possibly assist me but it’s worth the shot ! So my cycle has lasted 61 days & my period has been 25 days late . This is not regular to me I’ve been having pretty regular periods for the past few months. The only other thing i could think about is pregnancy but i have take urine test after urine test & it’s showing negative results so what do you guys think is going on & how long is it possible for someone to miss their period ?