Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Don't bother, they don't work!

These ovulation test strips do not work. I used them for 2 cycles and never got a darker test strip line than the control line. The seller promplty returned my money when I complained to them with no questions asked so obviously they know they don't work. I work in a science lab and perform testing on a daily basis so I am DEFINITELY not testing incorrectly. Don't waste your money, or more importantly your time. Some things are worth the money. Buy the brand name ones at the store!