False Negatives or change in cycle??

Hi guys, I stopped contraception 3 months ago and we started trying straight away. My first period and second period were both 28 days, my periods were very regular on contraception and before I started contraception and now my 3rd period is late. Im currently on cycle day 32 but with no positive pregnancy tests, no symptoms of period or anything of the sort. No moodiness which is normally the first sign of approaching period for me. Could the tests be false negative or is it possible to have a drastic change in cycle after coming off of contraception?