That happened to me so I took a test after I was a day late and it was negative, took another 4 days later and it was a definite positive. Good luck, I'll keep my fingers crossed for you.
I had a feeling I was pregnant and got a negative test. Then something prompted me to re test a week or so later and it was a positive. I never had regular periods n couldn't get pregnant for many years.
I got a negative last night and i was so devistated. but I'm a day late so I'm just praying it was just the wrong time and remaining hopeful!! head up!!