Irregular cycles

Can trying to conceive cause irregular cycles? AF come the at the same time and length every month, but this month and last month have been way off and that is when we started trying! my last month come days later, was way shorter, and lighter. this month has yet to come at all. i took a pregnancy test 2-3 weeks ago and they were negative and i'm extremely confused 🤷🏽‍♀️