Late Period / Negative Test

According to Glow my period was "scheduled" on the 10th of July. I never got it, I've had some cramping but nothing serious like I've had prior to many periods. I took a test Monday the 20th and it was negative. I've had periods every month until this month. There is still a week left of the month just uncertain on what to do? I have one more test left maybe take it in the morning? Anyone else have these issues?