Could they be wrong?

Hi ladies, really need some advice. I’m due for my period today, 28 day cycle. Usually get a bit of spotting/pink day 26/27 but have had nothing this cycle. Absolutely no symptoms apart from feeling extremely bloated 🙄. These are medicheck tests used in the sexual health clinic I work at with sensitivity of 25mol. Lines appeared within the time frame, almost instant. Could they be wrong? Do we trust the brand? FYI we haven’t actively been trying so this will be a shock 😐 all 3 are from the same urine as I wanted to make sure it wasn’t a dud 😐