What Causes Delayed Periods Post Recovery From Bronchitis?

I have acute bronchitis running it s course atm, and It will probably continue for a while. Another note, I am sexually active but my boyfriend and I are very careful and safe. There was only one time where we forgot protection, because it was in the moment and we were more thinking about each other and that moment. My period is about a week late, I have taken 2 pregnancy tests, did that yesterday. And both came out negative, plus i am experiencing NO other pregnancy symptoms other than a late period. I took a plan B about 4 days ago because a Condom broke on us. And I ve taken a plan B pill before, about 4 months ago, so my periods are irregular. BUT Could the bronchitis be causing my missed period? I am VERY reluctant to go see a Doctor, because i have a very bad fear of medical places and such. Plus i don t want my parents to know anything. I got the bronchitis about a week before i was suppose to start my period. Is there any chance I ll start my period next month? Or a way to make it start? Something specific? I just want my period back : ) Thank you so much!