Strange cycle....

So im over 2 weeks late but my SO and i had sex the last time june 26...not ovulating that week (im prettt sure). and i had a normal period in july. Glow is telling me i shoild start this month in 2 weeks. I dint have any signs of pregnancy other than exhaustion. I did have inlaws at my houee for 3 weeks and my mom just had e.r. surgery. Im thinking its stress but not sure. Any ideas?