Instruct: Classify Amazon reviews into positive or negative sentiment
Query: MAY NOT WORK FOR ALL

I have been using these OPKs and HPTs for 2 months now and have NOT got my POSITIVE on OPKs.... i even used the OPks on my husband pee for 3 days test the OPKs bcz mine were all negative.. so after testing him for 3 days he had all negatives... a man has a LH hormone surge ever 24-48 hrs...dr said some men dont have a surge for 4 days but my hub never got a postive so maybe he is one that doesnt have a surge for 4 days...i have alot of friends who use similiar test and have success but with me i never a postive..my dr said all women have different levels of hormone i am one that is naturally lower so i need sensitive OPKs... my friend and i wanted to test the HPTs and she is 14 weeks preggo... took them but just found out today;when i was talking to her; those test she took were accurate! she didnt know but she ws loosing the baby when she used the HPTs...i dont wanna say these horrible but you get what you pay for...