How accurate are blue dye tests??

Virginia • Wife, Mom of 4 handsome sons 💙💙💙💙👨‍👩‍👦‍👦🤰

I've always used the cheapies and stayed away from off brand blue dye tests. Is this positive or possibly an error? Please say a pray that this baby is a sticky bean! I've had a hard time with ectopic and chemical pregnancies before.