Positive at home and negative urine at doctor?

Has anyone had multiple positives at home and then a negative urine at the doctor?I have had three positives,faint but getting darker(period is due tomorrow)but went to my family doctor today to change some anxiety meds I’m on and they had my urine was negative with them.I peed right before I went and had to drink 2 bottled water to pee there and the doctor thinks that is what caused the false negative but it’s making me nervous!Any input would be appreciated!They did a blood test so just waiting to get those results back!