Positive tests?

I have been having faint lines two months in a row. They eventually go away, the lines have come back this month.. How am I suppose to know if they are real or not?

They are not the same tests I have used blue dyes and walmart brand and first response and accumed

Yes they are true positives they have light pink or blue lines.. I'm not sure why they would be faint for two months I'm thinking hormone imbalance