Helppp

So I’ve been off of birth control for over a year now. My periods have been regular, my overall cycle is pretty long, like 35 days from one period to the next. My husband and I still use condoms (don’t judge lmao) and I don’t think there were any issues with the ones we used but I am now 5 days late, I’ve taken 3 pregnancy tests and they’re all negative. I don’t feel stressed honestly because we are planning to start trying for children this fall so we are okay if we’re pregnant now. I just don’t understand what would make my period late for the first time in over a year. Any suggestions/thoughts??