when Should i test ? I'm 5 days late

My husband and I have been TTC for 8 months now .... I have been feeling very tired and have been having major headaches ... I tested a day before my period was due Which was Thursday   November 10 .... it was negative .... Now I'm 5 days late  still headaches and cramping since Friday   when my period was due .... it really feels like is coming ....now I'm on my 41 cycle my regular cycles are from 29-35 days.... when should I test again ?