I'm on cycle day 38 right now, I've never been this late and I'm usually regular but I took a test (not fmu) and it was negative. So I'm just waiting, I guess either for af to show up or for more symptoms that will indicate more hcg. If it's just a random missed period i don't want to miss these month's fertile Window so my question is can I go by the predicted window for if I'd gotten my period and maybe just extend it a little either side?