11 DPO... HELP

Okay so.. I’m 11 DPO and Glow says my period is 1 day late.. and Glow typically predicts my period correctly but I tested my ovulation for the first time this cycle and I ovulated around CD 18... and my cycle for the last 3 months has been about 27-28 days. Is this normal? Is this possible? I took a pregnancy test just now BUT it isn’t first morning urine and I had to basically make myself go and drank water right before and just had a little bit in my cup to test with. So is this even accurate? I’m desperate here 😢