First month ttc

Hi everyone I'm new to this group. This is my husband and my first month ttc. Within the last year i was diagnosed with hashimotos disease and just began medication this month. Over the last 2 weeks I have had waves of nausea and feel kind of spacey. My period was supposed to start Sunday but it hasn't yet. I'm pretty sure I ovulated on the 13th. Am I overthinking this? I took a pregnancy test a few days ago and got a bfn. I have no symptoms of my af coming. Should I test again?