Period is missing

My husband and I decided to start trying in June. My period is ALWAYS regular and I wasn’t concern about the problem I’m now having. For the past 5 years we have used condoms for birth control. So when we stopped using them I didn’t think my period would be messed up unless we did conceive. Well my period is now 10 days late and I’m getting a negative pregnancy test. Has anyone else had this problem when first trying? I’m so confused. I have spoke to my doctor and she thinks it’s my job stress and that it will regulate out, that I shouldn’t worry unless it gets around 6 weeks late. But I want to hear from others who may have had a similar experience.