Still no period, feel sick but negetive pregnancy test?

Me and my partner have been trying for nearly a year every month we cross r fingers but my period turns up like clockwork this month however its different. I keep coming over feeling sick and really not fancyin eating because of this. I was due monday however the previous tues i had light spotting which lasted a few hours. I just wanna know if anyone else is in my situation or has been in the same situation.