4 days late, negative HPT. So confused!

Jackie

My period is 4 days late and my period is never late! I’ve taken multiple HPT the last few days and they have all been negative. This morning I had very light brown spotting, which I thought was the beginning of my period. Turns out it’s not and my period still hasn’t came. I’m SO confused. My husband and I had sex the day before I ovulated (or when I think I was ovulating) so I could be pregnant. I don’t really have any other signs besides my nipples being slightly sore - which always happens before my period anyway.

Can anyone advise???? My husband and I have been trying for a few months.