Stumped 🤦‍♀️

Has anyone ever had this issue? I’m about 5 days late now and my period is never off or missed. I ovulated the 13th And was supposed to start my period the 28th. I took a test this afternoon and it was negative. Like,not even a faint line. Yes I know I should’ve waited till my first pee of the day but I couldn’t help it. But is it possible maybe my husband and I conceived a little later in the month like a week later or something and it just still be too early to get a positive result? I’m seriously stumped. Should I just make an appointment with my doctor? Wait a few more days? ...help🤦‍♀️