Help!

Anyone else been in this situation?

Period was due yesterday or the day before. Usually a 26/27 day cycle. Now on cycle day 28. Tests looked like it had the faintest line but I couldn’t tell if it was just an indent! Is it possible that my HCG is too low and it’ll become positive if I retest in a few days? My app says I ovulated the 14th May but I have no clue. Did anyone have negative tests the day of or day after missed period & then go on to having positive tests?

Symptoms: lots of watery & creamy cm, headaches, hunger, sore nipples