Ovulation hapnd but no period & pregnanc

Hi , I am 28 year old trying to concieve from the past three months.I had problem ovulating ,so my doctor had put me on letrozole2.5mg  for 5 days from Cycle day 2.March and April months I had my first and second letrozole doses and due to lockdown I was not able to go to hospital and monitor the follicle growth ,but the two months I got my periods on CD 32.For the month of May took letrozole went to hospital and did follicular study.Along with letrozole I had follisurge and hcg injections to help the follicle rupture. As expected I had two follicles in left and tight and found the right one grow up to 2cmd and ruptured too.My dic prescribed Dupasthon tab for 20days.From CD 34 for 7 days I had spotting and did a blood hcg test which came negative .today is my CD 41 my spotting has stopped and I have no periods too.I just want to understand what prevents my periods when the follicle had actually ruptured. I have got no ovarian cysts for sure and no other complaints like thyroid.